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”).

A339813
The exponent of the highest power of 2 dividing (A019565(n) - 1).
2
0, 1, 0, 2, 0, 1, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 5, 0, 1, 0, 2, 0, 2, 0, 1, 0, 7, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 2, 0, 1, 0, 5, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 4, 0, 1, 0, 2, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 1, 0
OFFSET
1,4
COMMENTS
The 2-adic valuation of A339809(n).
LINKS
FORMULA
a(n) = A007814(A339809(n)).
PROG
(PARI)
A019565(n) = { my(m=1, p=1); while(n>0, p = nextprime(1+p); if(n%2, m *= p); n >>= 1); (m); };
A339813(n) = valuation((A019565(n)-1), 2);
CROSSREFS
Cf. A007814, A339809, A339814 (bisection).
Sequence in context: A355742 A267860 A325488 * A178111 A178112 A324852
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 18 2020
STATUS
approved