Centered icosahedral number

Centered icosahedral number
Total no. of terms	Infinity
Subsequence of	Polyhedral numbers
Formula
First terms	1, 133, 55, 147, 309, 561, 923
OEIS index	A005902; Centered icosahedral;

A centered icosahedral number is a centered figurate number that represents an icosahedron. The centered icosahedral number for a specific n is given by

${\frac {(2n+1)\left(5n^{2}+5n+3\right)}{3}}$

The first such numbers are 1, 13, 55, 147, 309, 561, 923, 1415, 2057, 2869, 3871, 5083, 6525, 8217, …

References

Sloane, N. J. A. (ed.). "Sequence A005902 (Centered icosahedral (or cuboctahedral) numbers, also crystal ball sequence for f.c.c. lattice)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation..

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.