A365206 Centered octachoral numbers.
1, 49, 337, 1249, 3361, 7441, 14449, 25537, 42049, 65521, 97681, 140449, 195937, 266449, 354481, 462721, 594049, 751537, 938449, 1158241, 1414561, 1711249, 2052337, 2442049, 2884801, 3385201, 3948049, 4578337, 5281249, 6062161, 6926641, 7880449, 8929537
Offset: 1
Links
- Eric Weisstein's World of Mathematics, Figurate Number.
- Wikipedia, 8-cell.
- Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).
Programs
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Mathematica
Table[8*n^4 - 16*n^3 + 16*n^2 - 8n + 1, {n, 1, 100}]
Formula
a(n) = 8*n^4 - 16*n^3 + 16*n^2 - 8n + 1.
G.f.: x*(1 + 44*x + 102*x^2 + 44*x^3 + x^4)/(1 - x)^5. - Stefano Spezia, Aug 26 2023
Comments