A366820 a(n) is the sum of the divisors of n^n + 1.
3, 3, 6, 56, 258, 6264, 52136, 1559520, 17041416, 706911048, 10102223208, 706019328000, 9101898907920, 519285252355776, 11672709747324912, 880565163670372352, 18446811354131136516, 1792353900753729655758, 54357680125881245248800, 4154723599066412190910560
Offset: 0
Keywords
Links
- Eric Weisstein's World of Mathematics, Sierpinski Number of the First Kind
Programs
-
Mathematica
{3}~Join~Array[DivisorSigma[1, #^# + 1] &, 19] (* Michael De Vlieger, Oct 24 2023 *) -
PARI
a(n) = sigma(n^n+1);