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A367010
a(n) is the sum of the divisors of n*2^n + 1.
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
OFFSET
0,2
COMMENTS
The numbers n*2^n+1 are called Cullen numbers.
LINKS
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
KEYWORD
nonn,changed
AUTHOR
Sean A. Irvine, Oct 31 2023
STATUS
approved