A098719 Position of prime(n)# in A025487.

1, 2, 4, 9, 22, 54, 114, 246, 488, 948, 1809, 3327, 6020, 10624, 18246, 30726, 51148, 84074, 135598, 216398, 340886, 529051, 814237, 1240172, 1874464, 2817289, 4195918, 6186286, 9049492, 13121704, 18895821, 27199504, 38892092, 55318849, 78130780, 110028527

Offset: 1

Author

Jeff Burch, Sep 29 2004

Keywords

• nonn

Crossrefs

Cf. A002110, A025487.

Programs

Mathematica

Block[{nn = 24, f, s}, f[n_] := {{1}}~Join~Block[{lim = Product[Prime@ i, {i, n}], ww = NestList[Append[#, 1] &, {1}, n - 1], g}, g[x_] := Apply[Times, MapIndexed[Prime[First@ #2]^#1 &, x]]; Map[Block[{w = #, k = 1}, Sort@ Prepend[If[Length@ # == 0, #, #[[1]]], Product[Prime@ i, {i, Length@ w}]] &@ Reap[Do[If[# < lim, Sow[#]; k = 1, If[k >= Length@ w, Break[], k++]] &@ g@ Set[w, If[k == 1, MapAt[# + 1 &, w, k], PadLeft[#, Length@ w, First@ #] &@ Drop[MapAt[# + Boole[i > 1] &, w, k], k - 1]]], {i, Infinity}]][[-1]]] &, ww]]; s = Sort[Join @@ f@ nn]; {1}~Join~Array[Position[s, Product[Prime@ i, {i, #}]] &, nn][[All, 1, 1]]] (* Michael De Vlieger, Jul 23 2018 *)

Extensions

Extended by T. D. Noe, Nov 12 2010

More terms from Michael De Vlieger, Jul 23 2018

Name corrected by Amiram Eldar, Jun 05 2022