A328839 Smallest prime not dividing n times smallest prime not dividing A276087(n).

4, 15, 4, 21, 4, 25, 4, 21, 4, 33, 4, 15, 4, 33, 4, 21, 4, 25, 4, 39, 4, 39, 4, 15, 4, 39, 4, 51, 4, 21, 4, 21, 4, 15, 4, 25, 4, 33, 4, 39, 4, 15, 4, 39, 4, 39, 4, 25, 4, 51, 4, 51, 4, 15, 4, 51, 4, 33, 4, 21, 4, 33, 4, 21, 4, 25, 4, 39, 4, 39, 4, 15, 4, 51, 4, 51, 4, 25, 4, 51, 4, 57, 4, 15, 4, 39, 4, 57, 4, 21, 4, 39, 4, 51, 4

Offset: 1

Author

Antti Karttunen, Oct 29 2019

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..32768
• Index entries for sequences related to primorial numbers

Crossrefs

Cf. A010709 (odd bisection), A053669, A276086, A276087, A328578, A328579.

Cf. A328585 (positions of the prime squares).

Programs

PARI

A053669(n) = forprime(p=2, , if(n%p, return(p))); \\ From A053669
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A328579(n) = A053669(A276086(A276086(n)));
A328839(n) = (A053669(n) * A328579(n));

Formula

a(n) = A053669(n) * A328579(n).