This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A185147 #19 Mar 30 2012 17:22:57 %S A185147 1,1,1,1,1,1,2,1,1,1,2,1,3,1,1,2,2,1,1,1,1,3,1,3,2,2,1,3,1,1,1,5,1,1, %T A185147 2,3,3,1,1,4,2,1,2,2,1,1,2,4,1,2,2,1,2,2,1,1,2,5,1,2,2,1,1,1,1,6,1,1, %U A185147 1,4,2,1,2,5,1,1,1,1,1,2,1,5,1,1,3,3,1,3,7,1,3,6,1,1,1,1,2,1,3,2 %N A185147 Number of times each value of the sigma function occurs. %C A185147 The possible values of the sigma (sum of divisors) function are in A002191. Value A002191(n) occurs exactly a(n) times. Because sigma(x) >= x+1 (for x>1) with equality only at prime x, we know that for prime p, sigma(p) is the last time p+1 occurs as a value of sigma. This sequence is the same as A054973 without the zero terms. %H A185147 T. D. Noe, <a href="/A185147/b185147.txt">Table of n, a(n) for n = 1..10000</a> %t A185147 Transpose[Sort[Tally[DivisorSigma[1, Range[Prime[PrimePi[200]]]]]]][[2]] %Y A185147 Cf. A007370 (numbers for which a(n)=1). %K A185147 nonn %O A185147 1,7 %A A185147 _T. D. Noe_, Mar 18 2011