A136611 (0, 1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, ...) becomes (0, 1, 2, 3, 4^5, 6, 7*8, 9, 10^11, 12^13, 14*15, 16, 17^18*19, ...).

0, 1, 2, 3, 1024, 6, 56, 9, 100000000000, 106993205379072, 210, 16, 267198604589286774829171, 20, 462, 552, 2220446049250313080847263336181640625, 27

Offset: 0

Author

Juri-Stepan Gerasimov, Nov 08 2008

Keywords

• nonn

Comments

a(36) has 8261 decimal digits.

Examples

			a(4) = 4^5 = 1024,
a(6) = 7*8 = 56,
a(8) = 10^11 = 100000000000,
a(9) = 12^13 = 19216339899072,
a(10) = 14*15 = 210,
a(12) = 17^18*19 = 266314164608823014829171,
etc.
		

Links

• Michael De Vlieger, Table of n, a(n) for n = 0..35

Crossrefs

Cf. A141269, A141270.

Programs

Mathematica

j = k = 0; f[n_] := Flatten@ Riffle[Map[If[#2 == 1, {}, {"~Power~"}] & @@ # &, FactorInteger[n]], "~Times~"]; Array[(j = k; k += #2 + 1; ToExpression@ Apply[StringJoin, Riffle[Map[ToString, j + Range[0, #2]], #1]]) & @@ {#, Length[#]} &@ f[#] &, 22, 0] (* Michael De Vlieger, Oct 24 2022 *)

Extensions

a(9) and a(12) corrected and 2 terms appended by R. J. Mathar, Apr 14 2010

Offset 0 from Michael De Vlieger, Oct 24 2022