OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
407 is in the sequence because 407_d = 110010111_b and its largest proper divisor is 37_d = 100101_b is a substring. Also 407 is not prime nor congruent to 0 (modulo either 2, 3, 5 or 7).
MATHEMATICA
a = {}; Do[ If[ !PrimeQ[n] && Sort[Mod[n, {3, 5, 7}]][[1]] != 0 && StringPosition[ ToString[ FromDigits[ IntegerDigits[n, 2]]], ToString[ FromDigits[ IntegerDigits[ Divisors[n][[ -2]], 2]]]] != {}, a = Append[a, n]], {n, 3, 39960, 2}]; a
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Aug 08 2001; corrected Nov 13 2002
STATUS
approved