OFFSET
1,1
COMMENTS
Every integer of the form p*2^k, p = prime, k>=0, is in this sequence. Every integer of the form p*2^k, p = odd prime, is missing from sequence A162721.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
20 in binary is 10100. The distinct primes dividing 20 are 2 and 5, which are 10 and 101 in binary. Both 10 and 101 occur in 10100 (with overlapping). So 20 is in this sequence.
MATHEMATICA
q[n_] := AllTrue[FactorInteger[n][[;; , 1]], StringContainsQ[IntegerString[n, 2], IntegerString[#, 2]] &]; Select[Range[2, 100], q] (* Amiram Eldar, Nov 10 2021 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Jul 11 2009
EXTENSIONS
Corrected and extended by Sean A. Irvine, Dec 14 2009
STATUS
approved