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 A152986 #11 Jul 02 2021 11:25:15
%S A152986 0,0,11,11,10,18,67,71,60,32,187,351,30,46,519,337,128,220,577,483,
%T A152986 366,286,507,1153,248,336,2489,847,70,818,871,2181,1108,116,2861,2275,
%U A152986 694,130,2763,3645,100,2352,2823,1863,2278,158,3607,6617,636,920,6181,4019
%N A152986 Sum of proper divisors minus the number of proper divisors of pentagonal number A000326(n).
%H A152986 B. D. Swan, <a href="/A152986/b152986.txt">Table of n, a(n) for n = 1..10000</a>
%F A152986 a(n)=A001065(A000326(n))-A032741(A000326(n)) = A152770(A000326(n)).
%p A152986 A000326 := proc(n) n*(3*n-1)/2 ; end: A000203 := proc(n) numtheory[sigma](n) ; end: A000005 := proc(n) numtheory[tau](n) ; end: A152770 := proc(n) A000203(n)-A000005(n)-n+1 ; end: A152986 := proc(n) A152770(A000326(n)) ; end: for n from 1 to 80 do printf("%a,",A152986(n)) ; od: # _R. J. Mathar_, Jan 03 2009
%t A152986 DivisorSigma[1,#]-#-DivisorSigma[0,#]+1&/@PolygonalNumber[5,Range[60]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jul 02 2021 *)
%Y A152986 Cf. A000005, A000203, A000326, A001065, A032741, A152770.
%K A152986 easy,nonn,look
%O A152986 1,3
%A A152986 _Omar E. Pol_, Dec 22 2008
%E A152986 Extended by _R. J. Mathar_, Jan 03 2009