login
A257246
Even bisection of A257244: a(n) = A257244(2n).
5
2, 3, 3, 3, 3, 5, 3, 3, 3, 5, 7, 7, 3, 3, 7, 3, 5, 3, 5, 5, 11, 3, 13, 3, 13, 5, 11, 3, 7, 3, 13, 3, 13, 3, 5, 5, 11, 23, 3, 7, 3, 7, 3, 7, 3, 31, 3, 7, 13, 3, 7, 5, 7, 3, 31, 31, 3, 13, 41, 5, 3, 7, 19, 3, 7, 41, 41, 3, 19, 7, 29, 5, 3, 13, 11, 5, 3, 19, 3, 5, 5
OFFSET
1,1
FORMULA
a(n) = A257244(2n).
a(n) = A020639(A256393(2n)). [Equally, the smallest prime factor of A256393(2n).]
Other identities and observations:
For all n >= 1, a(n) <= A257245(n).
PROG
(Scheme, alternative definitions)
(define (A257246 n) (A257244 (+ n n)))
(define (A257246 n) (A020639 (A256393 (+ n n))))
CROSSREFS
Cf. also A257245 (the other bisection), A257247 (gives the positions where both bisections have the same value).
Sequence in context: A173924 A307392 A046886 * A056206 A257245 A329245
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 19 2015
STATUS
approved