login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A328319
Sum of digits when A328316(n) is written in primorial base; number of prime factors in A328316(1+n), counted with multiplicity.
5
0, 1, 1, 2, 1, 3, 3, 7, 21, 159, 12927, 132571335
OFFSET
0,4
FORMULA
a(n) = A276150(A328316(n)).
a(n) = A001222(A328316(1+n)).
PROG
(PARI)
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A328316(n) = if(!n, 0, A276086(A328316(n-1)));
A276150(n) = { my(s=0, p=2, d); while(n, d = (n%p); s += d; n = (n-d)/p; p = nextprime(1+p)); (s); };
\\ Or alternatively, more slowly as:
A328319(n) = bigomega(A328316(1+n));
KEYWORD
nonn,more,hard
AUTHOR
Antti Karttunen, Oct 14 2019
STATUS
approved