A367624 - OEIS

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

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OFFSET

1,2

COMMENTS

A123581(n) is odd if n is odd.

LINKS

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

MATHEMATICA

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

CROSSREFS

Cf. A007814, A123581.

Sequence in context: A337279 A157522 A059674 * A342748 A117545 A047000

Adjacent sequences: A367621 A367622 A367623 * A367625 A367626 A367627

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 06 2023

STATUS

approved