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

Offset: 0

Author

Zak Seidov, Oct 25 2009

Keywords

• base
• nonn

Examples

			{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}.
		

Crossrefs

Cf. A074600, A007496.

Programs

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 *)