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Heptagonal Number

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HeptagonalNumber

A heptagonal number is a polygonal number of the form n(5n-3)/2 for a positive integer n. The first few are 1, 7, 18, 34, 55, 81, 112, ... (OEIS A000566). The generating function for the heptagonal numbers is

(x(4x+1))/((1-x)^3)=x+7x^2+18x^3+34x^4+...

for |x|<1.

See also

Heptagonal Hexagonal Number, Heptagonal Pentagonal Number, Heptagonal Square Number, Heptagonal Triangular Number, Octagonal Heptagonal Number

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References

Sloane, N. J. A. Sequence A000566/M4358 in "The On-Line Encyclopedia of Integer Sequences."

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Heptagonal Number

Cite this as:

Weisstein, Eric W. "Heptagonal Number." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/HeptagonalNumber.html

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