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 A086454 #9 Feb 16 2025 08:32:50
%S A086454 1,2,2,3,2,2,4,3,2,2,5,2,2,2,3,4,2,2,6,2,2,2,2,3,2,2,2,7,2,2,2,2,5,2,
%T A086454 2,2,2,2,2,2,2,3,4,2,8,2,2,2,2,2,2,2,2,3,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
%U A086454 6,2,9,2,2,2,2,2,2,2,3,2,2,2,2,2,2,2,4,2,2,2,2,3,2,2,2,2,2,2,2,2,2
%N A086454 Number of divisors of prime powers: tau(p^e).
%H A086454 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DivisorFunction.html">Divisor Function</a>.
%H A086454 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimePower.html">Prime Power</a>.
%F A086454 a(n) = A000005(A000961(n)).
%F A086454 a(n) = e+1 for A000961(n) = p^e.
%F A086454 a(n) = A025474(n) + 1.
%t A086454 f[n_] := Module[{f = FactorInteger[n]}, If[Length[f] == 1, f[[1, 2]] + 1, Nothing]]; f[1] = 1; Array[f, 400] (* _Amiram Eldar_, Apr 09 2024 *)
%Y A086454 Cf. A000005, A000961, A025474, A086455.
%K A086454 nonn
%O A086454 1,2
%A A086454 _Reinhard Zumkeller_, Jul 20 2003