A096301 Product of nonzero digits(sum of digits(n^n)).

1, 4, 9, 3, 1, 14, 10, 21, 20, 1, 4, 20, 40, 10, 81, 64, 72, 8, 14, 3, 7, 32, 24, 15, 5, 20, 72, 18, 42, 18, 32, 10, 14, 8, 12, 14, 14, 60, 18, 2, 24, 15, 9, 30, 18, 30, 84, 27, 75, 5, 16, 8, 15, 168, 32, 27, 20, 56, 28, 24, 128, 20, 180, 224, 70, 15, 60, 120, 196, 90, 144, 200, 24

Offset: 1

Author

Jason Earls, Jun 25 2004

Keywords

• base
• easy
• nonn

Comments

Conjecture: a(n) = a(n+1) for infinitely many positive integers. Largest found is n=4462, i.e. pnd(sd(4462^4462)) = pnd(sd(4463^4463)) = 126.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A051801, A007953.

Programs

Mathematica

Array[Times@@Select[IntegerDigits[Total[IntegerDigits[#^#]]],#>0&]&,80] (* Harvey P. Dale, Sep 30 2012 *)