cp's OEIS Frontend

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.

A104886 Sequence A048138, the number of times that a positive integer occurs as the sum of proper divisors, if Goldbach partitions (two odd primes, which account for most of the values) are ignored.

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%I A104886 #1 Apr 09 2005 03:00:00
%S A104886 0,1,1,0,2,1,2,0,1,0,1,1,2,1,2,0,1,0,2,1,2,0,1,0,1,0,1,0,1,2,2,1,1,0,
%T A104886 1,0,1,0,3,1,2,1,2,0,2,0,1,1,2,0,0,0,2,1,1,2,1,0,1,0,2,1,3,1,1,0,1,0,
%U A104886 1,0,1,2,3,0,3,0,1,0,1,2,1,0,1,0,1,1,0,1,2,0,2,0,1,0,0,2
%N A104886 Sequence A048138, the number of times that a positive integer occurs as the sum of proper divisors, if Goldbach partitions (two odd primes, which account for most of the values) are ignored.
%F A104886 a(n) = number of m such that the sum of the proper divisors of m is n, ignoring m if m is the product of two different odd primes.
%e A104886 a(13)=1 because s(27)=1+3+9 and s(35)=1+5+7=13 however 35's factors 3 and 5 are a Goldbach partition, so 35 is not counted.
%Y A104886 Cf. A048138, A001065, A061358.
%K A104886 nonn
%O A104886 2,5
%A A104886 Nathan McNew (agreatnate(AT)yahoo.com), Mar 29 2005