A175514 - OEIS

A175514

Numbers n such that the base-2 expansion of n ends with the base-5 expansion of n.

0, 1, 30, 31, 3900, 3901, 93900, 93901, 97000, 97001, 1270000000, 1270000001, 496864267596900, 496864267596901, 596044970707000, 596044970707001, 300522773449238130, 300522773449238131, 1549835974179703900, 1549835974179703901, 39043445740978906900, 39043445740978906901, 1156389717140148910000

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OFFSET

1,3

COMMENTS

Terms occur in pairs {10k,10k+1}.

LINKS

Max Alekseyev, Table of n, a(n) for n = 1..28

MATHEMATICA

n=0; nmax=10^8; While[n<=nmax, a=IntegerDigits[n, 2]; L=Length[a]; b=FromDigits[a, 5];

If[Mod[b, 2^L]==n, Print[{b, b+1}]]; n=n+2]; (* after Ray Chandler *)

CROSSREFS

Cf. A169828.