A367010 - OEIS

A367010

a(n) is the sum of the divisors of n*2^n + 1.

1, 4, 13, 31, 84, 192, 576, 1344, 2736, 5040, 13680, 24276, 56000, 153842, 308416, 538920, 1110276, 2909040, 5495040, 14446080, 31374720, 45955008, 106119552, 233997312, 527587200, 1184932800, 3247522560, 4365239040, 7784309910, 16265125632, 36250560000

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OFFSET

0,2

COMMENTS

The numbers n*2^n+1 are called Cullen numbers.

LINKS

Amiram Eldar, Table of n, a(n) for n = 0..865

FORMULA

a(n) = sigma(n*2^n + 1) = A000203(A002064(n)).

MATHEMATICA

DivisorSigma[1, Table[n*2^n+1, {n, 0, 30}]] (* Paul F. Marrero Romero, Dec 17 2023 *)

CROSSREFS