A367624 2-adic valuation of A123581(2*n).

1, 2, 2, 1, 1, 3, 1, 3, 1, 2, 2, 1, 4, 1, 4, 1, 1, 2, 1, 2, 1, 3, 1, 2, 3, 1, 2, 1, 1, 5, 1, 2, 5, 1, 2, 1, 3, 1, 3, 1, 1, 2, 1, 2, 1, 4, 1, 2, 4, 1, 2, 1, 3, 1, 1, 3, 1, 2, 2, 1, 6, 1, 1, 6, 1, 2, 1, 2, 1, 3, 3, 1, 2, 1, 1, 2, 1, 4, 1, 4, 1, 2, 1, 3, 2, 1, 3, 1, 2, 1, 5, 1, 2, 1

Offset: 1

Author

N. J. A. Sloane, Dec 06 2023

Keywords

• nonn

Comments

A123581(n) is odd if n is odd.

Links

• N. J. A. Sloane, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A007814, A123581.

Programs

Mathematica

With[{nmax=100},IntegerExponent[NestList[#+FactorInteger[#][[-1,1]]&,3,2nmax-1][[2;;-1;;2]],2]] (* Paolo Xausa, Dec 07 2023 *)