A165820 - OEIS

A165820

a(n) = the smallest positive integer that, when written in binary, contains both binary n and binary n^2 as substrings.

%I #17 Mar 03 2018 09:48:00

%S 1,4,19,16,89,100,113,64,593,1380,377,400,425,452,481,256,4385,1298,

%T 723,10640,5561,11748,8471,18456,1649,1700,729,1808,1865,1924,1985,

%U 1024,33857,9250,36041,75024,5477,11558,40433,83520,1681,87780,22329,92048

%N a(n) = the smallest positive integer that, when written in binary, contains both binary n and binary n^2 as substrings.

%H Rémy Sigrist, <a href="/A165820/b165820.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A294977(n, n^2). - _Rémy Sigrist_, Mar 03 2018

%t f[n_] := Block[{k = 1, is = IntegerString[n, 2], iss = IntegerString[n^2, 2]}, While[ StringPosition[ IntegerString[k, 2], is] == {} || StringPosition[ IntegerString[k, 2], iss] == {}, k++ ]; k]; Array[f, 44] (* _Robert G. Wilson v_, Oct 02 2009 *)

%Y Cf. A007088, A001737.

%Y Cf. A165819, A165821, A165822, A294977.

%K base,nonn

%O 1,2

%A _Leroy Quet_, Sep 28 2009

%E a(7)-a(44) from _Robert G. Wilson v_, Oct 02 2009