Centered icosahedral number

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

$(2n+1)\times{(5n^2+5n+3) \over 3}$

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

References

• "Sloane's A005902 : Centered icosahedral (or cuboctahedral) numbers, also crystal ball sequence for f.c.c. lattice", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation..