A114599 a(1) = a(2) = 1. For n >= 3, a(n) = 1 + A114600(n-2)*A114600(n-1).

1, 1, 2, 3, 7, 22, 78, 144, 40, 16, 11, 23, 254, 2922, 61850, 602420, 409448, 42038, 2669414, 38065410, 255320214, 315752716934, 22408767609924, 18684193273697426172, 85136306795697966858, 4400725717987783759574480, 620164474859666893438157645258582

Offset

1,3

Links

Amiram Eldar, Table of n, a(n) for n = 1..39

Example

13 is the greatest prime dividing a(7) = 78 and 3 is the greatest prime dividing a(8) = 144. So a(9) = 1 + 13*3 = 40.

Mathematica

f[n_] := If[n == 1, 1, FactorInteger[n][[ -1, 1 ]]]; g[l_] := Append[l, 1 + Times @@ f /@ Take[l, -2]]; Nest[g, {1, 1}, 30] (* Ray Chandler, Dec 26 2005 *)

Crossrefs

Cf. A006530, A114600.

Sequence in context: A187014 A053966 A010738 * A094062 A038159 A077210

Adjacent sequences: A114596 A114597 A114598 * A114600 A114601 A114602

Keyword

nonn

Author

Leroy Quet, Dec 13 2005

Extensions

Extended by Ray Chandler, Dec 26 2005

a(27) from Amiram Eldar, Oct 27 2024

Status

approved