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 A152987 #8 Dec 08 2015 03:19:31 %S A152987 0,0,0,0,0,0,6,11,35,47,57,16,0,98,187,146,176,184,525,326,1525,1007, %T A152987 254,1632,1275,4261,3311,2859,1476,7489,4383,4408,7624,9859,7450,0, %U A152987 5428,9086,38472,50191,29898,33867,41264,22030,47947,109323,107783,77168 %N A152987 Sum of proper divisors minus the number of proper divisors of the number of partitions of n, A000041(n). %C A152987 Note that if a(n) != 0 then the number of partitions of n (A000041(n)) is a composite number (A002808), otherwise A000041(n) is a noncomposite number (A008578). See A152770. %F A152987 a(n) = A001065(A000041(n)) - A032741(A000041(n)) = A152770(A000041(n)). %p A152987 A000041 := proc(n) combinat[numbpart](n) ; end: A001065 := proc(n) numtheory[sigma](n)-n ; end: A032741 := proc(n) if n = 0 then 0; else numtheory[tau](n)-1 ; fi; end: A152987 := proc(n) local np ; np := A000041(n) ; A001065(np)-A032741(np) ; end: for n from 1 to 80 do printf("%d,",A152987(n)) ; end: # _R. J. Mathar_, Jan 22 2009 %Y A152987 Cf. A000005, A000041, A000203, A001065, A002808, A008578, A032741, A152770. %K A152987 easy,nonn %O A152987 1,7 %A A152987 _Omar E. Pol_, Dec 21 2008 %E A152987 More terms from _R. J. Mathar_, Jan 22 2009