Voozh

A152493

Numbers k such that the decimal expansion of 2^k+5^k contains no 0's (probably 58 is last term).

0, 1, 2, 3, 4, 5, 6, 7, 9, 10, 12, 16, 17, 18, 30, 37, 58

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..16.

EXAMPLE

{n,2^n+5^n}: {0,2}, {1,7}, {2,29}, {3,133}, {4,641}, {5,3157}, {6,15689}, {7,78253}, {9,1953637}, {10,9766649}, {12,244144721}, {16,152587956161}, {17,762939584197}, {18,3814697527769}, {30,931322574616552257449}, {37,72759576141834396472156597}, {58,34694469519536141888238777858214286477369}.

MATHEMATICA

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

Select[Range[0, 10000], DigitCount[2^#+5^#, 10, 0]==0&] (* Harvey P. Dale, Oct 14 2011 *)

CROSSREFS

Cf. A074600, A007496.

Sequence in context: A261040 A087950 A060527 * A388653 A229028 A079002

Adjacent sequences: A152490 A152491 A152492 * A152494 A152495 A152496

KEYWORD

base,nonn

AUTHOR

Zak Seidov, Oct 25 2009

STATUS

approved

URL: https://oeis.org/A152493

⇱ A152493 - OEIS