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 A152774 #8 Apr 07 2024 09:09:26 %S A152774 0,0,1,1,1,3,1,3,3,3,1,14,1,3,7,7,1,15,3,15,7,3,1,71,5,3,15,15,1,63,3, %T A152774 15,7,3,7,159,7,7,7,63,3,63,1,31,31,7,1,335,7,47,7,15,3,127,15,95,31, %U A152774 7,3,959,3,7,31,63,7,63,7,31,31,127,3,1535,3,15,47,31,15,127,3 %N A152774 Number of proper divisors of the Fibonacci number A000045(n). %H A152774 Amiram Eldar, <a href="/A152774/b152774.txt">Table of n, a(n) for n = 1..1422</a> %F A152774 a(n) = A000005(A000045(n))-1 = A032741(A000045(n)) = A063375(n)-1. %t A152774 a[n_] := DivisorSigma[0, Fibonacci[n]] - 1; Array[a, 100] (* _Amiram Eldar_, Apr 07 2024 *) %o A152774 (PARI) a(n) = numdiv(fibonacci(n)) - 1; \\ _Amiram Eldar_, Apr 07 2024 %Y A152774 Cf. A000005, A032741, A063375, A074283, A152990. %K A152774 nonn %O A152774 1,6 %A A152774 _Omar E. Pol_, Jan 17 2009