A106844 - OEIS

A106844

Exponent of 2 in the prime factorization of A093641(n).

0, 1, 0, 2, 0, 1, 0, 3, 1, 0, 2, 0, 1, 4, 0, 0, 2, 1, 0, 3, 1, 2, 0, 0, 5, 1, 0, 1, 3, 0, 0, 2, 1, 0, 4, 2, 0, 3, 1, 0, 0, 1, 6, 0, 2, 0, 0, 1, 2, 0, 4, 1, 0, 1, 3, 0, 2, 1, 5, 0, 0, 0, 3, 1, 0, 0, 4, 0, 2, 1, 1, 2, 0, 7, 0, 1, 3, 0, 0, 1, 1, 2, 0, 0, 3, 0, 1, 5, 0, 2, 1, 0, 2, 0, 4, 1, 0, 0, 3, 2, 0, 6, 0, 1

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,4

COMMENTS

Write down all numbers of form 2^i*prime(j), j>0, i>=0, sort them, then extract i.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A007814(A093641(n)).

MATHEMATICA

f[n_] := Module[{e = IntegerExponent[n, 2]}, If[!CompositeQ[n / 2^e], e, Nothing]]; Array[f, 200] (* Amiram Eldar, Aug 24 2024 *)

CROSSREFS