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 A357050 #4 Dec 15 2022 13:52:57
%S A357050 2,1,1,4,4,7,2,2,10,2,2,32,2,1,26,1,6,24,1,19,20,2,1,1,20,4,1,270,11,
%T A357050 14,1,14,116,12,9,12,3,195,1,2,719,1,42,1,8,9,8,2,148,142,6,1,8,6,6,
%U A357050 2154,1,534,1,6,125,108,1,6,117,1,447,4
%N A357050 Number of ways A005101(n)+1 can be written as sum of a subset of the proper divisors of A005101(n), the n-th abundant number.
%C A357050 Obviously, for non abundant numbers (including perfect numbers) N, there is no way to write N+1 as the sum of a subset of N's proper divisors. Therefore we consider only abundant N = A005101(n) here.
%C A357050 The first zero appears for the seventh weird and primitive weird number A006037(7) = A002975(7) = 9272 = A005101(2310) (which surprisingly is w = A100696(1), the first weird number such that the sum of its divisors less than its abundance A033880(w) is larger than that).
%o A357050 (PARI) {A357050(n)= sum(b=1, -1+2^#d=divisors(n)[^-1], vecsum(vecextract(d,b))==n+1)} \\ not very efficient, better use code as in is_A005835().
%Y A357050 Cf. A005101, A006037, A002975, A005835 (abundant, weird, primitive weird and pseudoperfect numbers).
%Y A357050 Cf. A033880 (abundance), A100696.
%K A357050 nonn
%O A357050 1,1
%A A357050 _M. F. Hasler_, Dec 13 2022