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 A341624 #6 Feb 24 2021 08:19:12 %S A341624 0,0,0,0,0,1,0,0,0,0,0,2,0,0,0,0,0,2,0,1,0,0,0,3,0,0,0,1,0,2,0,0,0,0, %T A341624 0,4,0,0,0,2,0,2,0,0,0,0,0,4,0,0,0,0,0,3,0,2,0,0,0,5,0,0,0,0,0,2,0,0, %U A341624 0,1,0,6,0,0,0,0,0,2,0,3,0,0,0,5,0,0,0,1,0,4,0,0,0,0,0,5,0,0,0,2,0,2,0,1,0,0,0,6,0,0,0,3,0,2,0,0,0,0,0,1 %N A341624 a(n) = 0 if n is a deficient number, otherwise a(n) is the number of nondeficient divisors of the last number in the iteration x -> A003961(x) (starting from x=n) for which that count (A341620) is nonzero. %H A341624 Antti Karttunen, <a href="/A341624/b341624.txt">Table of n, a(n) for n = 1..65537</a> %H A341624 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %H A341624 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %o A341624 (PARI) %o A341624 A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); }; %o A341624 A341620(n) = sumdiv(n,d,(sigma(d)>=(2*d))); %o A341624 A341624(n) = { my(t, u=0); while((t=A341620(n))>0, u=t; n = A003961(n)); (u); }; %Y A341624 Cf. A005100 (positions of zeros). %Y A341624 Differs from A341620 for the first time at n=120, where a(120)=1, while A341620(120)=8. %Y A341624 Cf. also A341508, A341618. %K A341624 nonn %O A341624 1,12 %A A341624 _Antti Karttunen_, Feb 22 2021