A385289 Numbers whose trailing digits form a power of 2.

1, 2, 4, 8, 11, 12, 14, 16, 18, 21, 22, 24, 28, 31, 32, 34, 38, 41, 42, 44, 48, 51, 52, 54, 58, 61, 62, 64, 68, 71, 72, 74, 78, 81, 82, 84, 88, 91, 92, 94, 98, 101, 102, 104, 108, 111, 112, 114, 116, 118, 121, 122, 124, 128, 131, 132, 134, 138, 141, 142, 144, 148

Offset: 1

Author

Stefano Spezia, Jun 24 2025

Keywords

• nonn
• base
• easy

Links

• Stefano Spezia, Table of n, a(n) for n = 1..10000

Crossrefs

Union of A000079 and A384714.

Cf. A209229.

Programs

Mathematica

Select[Range[150],Sum[Boole[IntegerQ[Log2[FromDigits[Drop[IntegerDigits[#],i]]]]],{i,0,IntegerLength[#]}]>0 &]

PARI

isp2(k) = k==1<A209229
isok(k) = if (isp2(k), return(1)); for (i=1, oo, my(z=k % 10^i); if (z==k, return(0), if (z && isp2(z), return(1)))); return(0); \\ Michel Marcus, Jun 24 2025