A141288 a(0)=1. a(n) = smallest positive multiple of a(n-1) such that a(n) contains the binary representation of n at least once somewhere within its binary representation.

1, 1, 2, 6, 12, 84, 252, 252, 504, 2520, 17640, 52920, 52920, 52920, 52920, 476280, 952560, 952560, 4762800, 61916400, 185749200, 928746000, 928746000, 928746000, 928746000, 4643730000, 13931190000, 13931190000, 13931190000, 13931190000

Offset

0,3

Links

Table of n, a(n) for n=0..29.

Example

6 in binary is 110. Checking the multiples of a(5)=84: 1*84 = 84 = 1010100 in binary. 110 does not occur. 2*84 = 168 = 10101000 in binary. 110 does not occur. But 3*84 = 252 = 11111100 in binary. 110 occurs in this like so: 1111(110)0. So a(6) = 252.

Maple

contai := proc(a, n) verify(convert(n, base, 2), convert(a, base, 2), sublist) ; end: A141288 := proc(n) option remember; local k ; if n= 0 then 1; else for k from 1 do if contai(k*procname(n-1), n) then RETURN( k*procname(n-1) ) ; fi; od: fi; end: seq(A141288(n), n=0..40) ; # R. J. Mathar, Feb 19 2009

Crossrefs

Sequence in context: A226178 A129085 A274941 * A038787 A144098 A259140

Adjacent sequences: A141285 A141286 A141287 * A141289 A141290 A141291

Keyword

base,nonn

Author

Leroy Quet, Aug 01 2008

Extensions

Extended by R. J. Mathar, Feb 19 2009

Status

approved