A190896 Least positive integer whose binary representation does not occur in the concatenation of the binary representations of all earlier terms.

1, 2, 3, 4, 8, 10, 13, 15, 16, 19, 20, 32, 35, 37, 38, 40, 49, 54, 61, 64, 67, 68, 73, 74, 79, 80, 85, 87, 93, 103, 117, 121, 127, 128, 131, 134, 136, 139, 141, 143, 148, 151, 152, 155, 156, 158, 160, 165, 166, 170, 172, 174, 182, 193, 197, 217, 218, 239, 241, 251, 256, 259, 262, 264, 267, 268

Offset

0,2

Comments

See the variant A118250 for comments and examples.

Links

Table of n, a(n) for n=0..65.

Prog

(PARI) A190896(n, show=0, a=1)={my(c=[0], S=[], L); for(k=1, n, show && print1(a", "); while( setsearch(S, binary(a++)), ); c=concat(c, binary(a)); S=[]; for(i=0, #c-L=#binary(a), c[i+1] & for(j=i+L, min(i+L+1, #c), S=setunion(S, Set(t=[vecextract(c, 2^j-2^i)]))))); a}

Crossrefs

Cf. A190897 (concatenation of binary representations), A118248 (the same with nonnegative integers), A118250, A118252 (variants where binary representations are reversed).

Sequence in context: A061193 A346971 A180941 * A365018 A135772 A209064

Adjacent sequences: A190893 A190894 A190895 * A190897 A190898 A190899

Keyword

easy,nonn,base

Author

M. F. Hasler, Dec 29 2012

Status

approved