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 A096625 #19 Apr 19 2025 10:35:16
%S A096625 1,1,1,2,2,2,2,6,3,3,3,3,3,3,3,12,12,12,12,12,12,12,12,12,12,12,12,12,
%T A096625 12,12,12,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,
%U A096625 60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60,60
%N A096625 Denominators of the Riemann prime counting function.
%D A096625 Paulo Ribenboim, The Little Book of Bigger Primes, Springer-Verlag NY 2004. See p. 167.
%H A096625 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RiemannPrimeCountingFunction.html">Riemann Prime Counting Function</a>
%e A096625 0, 1, 2, 5/2, 7/2, 7/2, 9/2, 29/6, 16/3, 16/3, 19/3, ...
%t A096625 Table[Sum[PrimePi[x^(1/k)]/k, {k, Log2[x]}], {x, 100}] // Denominator (* _Eric W. Weisstein_, Jan 09 2019 *)
%o A096625 (PARI) a(n) = denominator(sum(k=1, n, if (p=isprimepower(k), 1/p))); \\ _Michel Marcus_, Jan 07 2019
%o A096625 (PARI) a(n) = denominator(sum(k=1, logint(n, 2), primepi(sqrtnint(n, k))/k)); \\ _Daniel Suteu_, Jan 07 2019
%Y A096625 Cf. A096624.
%K A096625 nonn,frac
%O A096625 1,4
%A A096625 _Eric W. Weisstein_, Jul 01 2004