A097366 Largest k such that 2^k divides A096421(n).

1, 2, 2, 3, 3, 5, 4, 8, 5, 7, 6, 7, 7, 10, 8, 9, 9, 11, 10, 11, 11, 13, 12, 15, 13, 16, 14, 17, 15, 17, 16, 18, 17, 21, 18, 19, 19, 21, 20, 23, 21, 23, 22, 23, 23, 27, 24, 27, 25, 27, 26, 27, 27, 29, 28, 30, 29, 33, 30, 31, 31, 33, 32, 34, 33, 35, 34, 36, 35, 38, 36, 39, 37, 39, 38

Offset

3,2

Comments

Exponent of 2 in prime factorization of A096421(n).

Observation: a(n) = (n-1)/2 for odd n.

Links

Table of n, a(n) for n=3..77.

Example

A096421(10) = 1792 = 2^8 * 7, so a(10) = 8.

Prog

(PARI) {m=77; v=vector(m); v[1]=1; for(n=2, m, s=0; for(j=1, n-1, if(gcd(j, n)==1, s=s+v[j]*v[n-j])); v[n]=s); for(i=3, m, print1(factor(v[i])[1, 2], ", "))}

Crossrefs

Cf. A096421, A097365.

Sequence in context: A036819 A351004 A114328 * A139807 A308465 A276119

Adjacent sequences: A097363 A097364 A097365 * A097367 A097368 A097369

Keyword

nonn

Author

Klaus Brockhaus, Aug 09 2004

Status

approved