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 A116432 #8 Sep 02 2024 13:04:19
%S A116432 1,1,2,4,5,7,12,18,24,37,54,74,107,159,218,315,450,634,888,1269,1782,
%T A116432 2496,3520,4933,6899,9681,13555,18888,26407,36855,51352,71526,99654,
%U A116432 138608,192708,267833,372107,516420,716816,994191,1378195,1909694
%N A116432 The number of n-almost primes less than or equal to e^n, starting with a(0)=1.
%t A116432 AlmostPrimePi[k_Integer, n_] := Module[{a, i}, a[0] = 1; If[k == 1, PrimePi[n], Sum[PrimePi[n/Times @@ Prime[ Array[a, k - 1]]] - a[k - 1] + 1, Evaluate[ Sequence @@ Table[{a[i], a[i - 1], PrimePi[(n/Times @@ Prime[Array[a, i - 1]])^(1/(k - i + 1))]}, {i, k - 1}]] ]]]; (* _Eric W. Weisstein_, Feb 07 2006 *)
%t A116432 Table[ AlmostPrimePi[n, E^n], {n, 42}]
%Y A116432 Cf. A078840, A078841, A078842, A116432, A078843, A116426, A078844, A116427, A078845, A116428, A116429, A116430, A078846, A116431.
%K A116432 nonn
%O A116432 0,3
%A A116432 _Robert G. Wilson v_, Feb 10 2006