

A152520


Numbers n such that the decimal expansion of 2^n+5^n contains no 2's and no 5's (probably 11 is the last term).


0




OFFSET

1,2


LINKS

Table of n, a(n) for n=1..6.


EXAMPLE

{n, 2^n+5^n}:{1,7}, {3,133}, {4,641}, {8,390881}, {10,9766649}, {11,48830173}.


MATHEMATICA

Do[If[Intersection[IntegerDigits[p=2^n+5^n], {2, 5}]=={}, Print[{n, p}]], {n, 0, 2000}]


CROSSREFS

Cf. A074600, A007496, A152493.
Sequence in context: A253606 A258640 A185726 * A239976 A191193 A327185
Adjacent sequences: A152517 A152518 A152519 * A152521 A152522 A152523


KEYWORD

base,nonn


AUTHOR

Zak Seidov, Oct 25 2009


STATUS

approved



