A151764 a(n) = f(f(n)), where f(n) = A071786(n).

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 217, 20, 21, 22, 32, 24, 25, 26, 27, 28, 128, 30, 31, 32, 33, 34, 35, 36, 37, 434, 39, 40, 14, 42, 142, 44, 45, 64, 146, 48, 49, 50, 51, 52, 35, 54, 55, 56, 651, 256, 455, 60, 16, 62, 63, 64, 65, 66, 364, 68, 96, 70

Offset: 1

Author

N. J. A. Sloane, Jun 22 2009, Jun 23 2009

Keywords

• nonn
• base
• mult

Comments

Completely multiplicative.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Index to divisibility sequences

Crossrefs

Cf. A071786.

Programs

Haskell

a151764 = a071786 . a071786 -- Reinhard Zumkeller, Oct 14 2011

PARI

rev(n)=fromdigits(Vecrev(digits(n)))
A071786(n)=my(f=factor(n)); prod(i=1,#f~,rev(f[i,1])^f[i,2])
a(n)=A071786(A071786(n)) \\ Charles R Greathouse IV, Jun 28 2015