OFFSET
1,1
COMMENTS
Terms in the sequence cannot end in 00, 0010, 001010, etc., and thus a(n) > 3n/2 + O(log n). - Charles R Greathouse IV, Apr 21 2015
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
PROG
(Haskell)
a090421 n = a090421_list !! (n-1)
a090421_list = filter ((> 0) . a090418) [1..]
-- Reinhard Zumkeller, Aug 06 2012
(PARI) is_A090421(n)={isprime(n) || if(bittest(n, 0), for(k=2, #binary(n)-2, bittest(n, k-1) && isprime(n%2^k) && is_A090421(n>>k) && return(1)), bittest(n, 1) && is_A090421(n>>2))} \\ Charles R Greathouse IV and M. F. Hasler, Apr 21 2015
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Nov 30 2003
EXTENSIONS
Based on corrections in A090418, data recomputed by Reinhard Zumkeller, Aug 06 2012
STATUS
approved