A367010 - OEIS

%I #13 Oct 28 2024 09:35:37

%S 1,4,13,31,84,192,576,1344,2736,5040,13680,24276,56000,153842,308416,

%T 538920,1110276,2909040,5495040,14446080,31374720,45955008,106119552,

%U 233997312,527587200,1184932800,3247522560,4365239040,7784309910,16265125632,36250560000

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

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

%H Amiram Eldar, <a href="/A367010/b367010.txt">Table of n, a(n) for n = 0..865</a>

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

%t DivisorSigma[1, Table[n*2^n+1, {n,0,30}]] (* _Paul F. Marrero Romero_, Dec 17 2023 *)

%Y Cf. A002064, A000203, A063515, A367007, A367009.

%K nonn

%O 0,2

%A _Sean A. Irvine_, Oct 31 2023