A161600 Nonprime numbers such that TITO(n) = n, where TITO(n) = A161594(n).

1, 4, 6, 8, 9, 22, 26, 33, 39, 44, 46, 55, 62, 66, 69, 77, 82, 86, 88, 93, 99, 121, 143, 169, 187, 202, 206, 226, 242, 252, 253, 262, 286, 299, 303, 309, 339, 341, 343, 363, 393, 404, 422, 446, 451, 466, 473, 482, 484, 505, 525, 583, 606, 616, 622, 626, 633, 662, 669, 671, 682, 686

Offset: 1

Author

J. H. Conway & Tanya Khovanova, Jun 14 2009

Keywords

• nonn
• base

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• T. Khovanova, Turning Numbers Inside Out [From _Tanya Khovanova_, Jul 07 2009]

Crossrefs

Cf. A010051, A161594; subsequence of A161597.

Programs

Haskell

a161600 n = a161600_list !! (n-1)
a161600_list = filter ((== 0) . a010051) a161597_list
-- Reinhard Zumkeller, Oct 14 2011

Mathematica

reversepower[{n_, k_}] := FromDigits[Reverse[IntegerDigits[n]]]^k; f[n_] := FromDigits[Reverse[IntegerDigits[Times @@ Map[reversepower, FactorInteger[n]]]]]; Select[Range[600], f[#] == # && ! PrimeQ[#] &]

PARI

is(n)=!isprime(n)&&n==A161594(n) \\ M. F. Hasler, May 11 2015

Extensions

Edited by N. J. A. Sloane, Jun 23 2009

Offset corrected by Reinhard Zumkeller, Oct 14 2011

Minor edits and more displayed terms from M. F. Hasler, May 11 2015