Heptagonal numbers
Heptagonal Hep*tag"o*nal, a. [Cf. F. heptagonal.] Having seven angles or sides. [1913 Webster]

{Heptagonal numbers} (Arith.), the numbers of the series 1, 7, 18, 34, 55, etc., being figurate numbers formed by adding successively the terms of the arithmetical series 1, 6, 11, 16, 21, etc. [1913 Webster]

The Collaborative International Dictionary of English. 2000.

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• Heptagonal — Hep*tag o*nal, a. [Cf. F. heptagonal.] Having seven angles or sides. [1913 Webster] {Heptagonal numbers} (Arith.), the numbers of the series 1, 7, 18, 34, 55, etc., being figurate numbers formed by adding successively the terms of the… …   The Collaborative International Dictionary of English

• Heptagonal number — A heptagonal number is a figurate number that represents a heptagon. The n th heptagonal number is given by the formula :frac{5n^2 3n}{2}.The first few heptagonal numbers are:1, 7, 18, 34, 55, 81, 112, 148, 189, 235, 286, 342, 403, 469, 540, 616 …   Wikipedia

• Heptagonal pyramidal number — A heptagonal pyramidal number is the sum of the first few heptagonal numbers. The heptagonal number for n can be calculated by adding up the heptagonal numbers for 1 to n , or by using the formula n ( n + 1)(5 n 2)/6.The first few heptagonal… …   Wikipedia

• Centered heptagonal number — A centered heptagonal number is a centered figurate number that represents a heptagon with a dot in the center and all other dots surrounding the center dot in successive heptagonal layers. The centered heptagonal number for n is given by the… …   Wikipedia

• List of prime numbers — This is an incomplete list, which may never be able to satisfy particular standards for completeness. You can help by expanding it with reliably sourced entries. By Euclid s theorem, there are an infinite number of prime numbers. Subsets of the… …   Wikipedia

• 70 (number) — ← 69 71 → 70 ← 70 71 72 73 74 75 76 …   Wikipedia

• 7 (number) — Seven redirects here. For other uses, see Seven (disambiguation). 7 −1 0 1 2 3 4 5 6 7 8 9 → List of numbers Integers …   Wikipedia

• 1000 (number) — List of numbers Integers ← 1k 2k 3k 4k 5k 6k 7k 8k 9k → Cardinal 1000 one thousand …   Wikipedia

• 2000 (number) — 2000 (two thousand) is the natural number following 1999 and preceding 2001.See also: millennium, year 2000 AD, Y2K, 2000 (disambiguation).Two thousand is the highest number expressible using only two unmodified characters in roman numerals… …   Wikipedia

• Dice — For other uses, see Dice (disambiguation). Four coloured dice showing all six possible sides (on a right handed, 6 sided die with pips) A die (plural dice, from Old French dé, from Latin datum something which is given or played )[1] …   Wikipedia