A158572 a(n) = A007814((2n-1)!! - 1).

1, 1, 3, 4, 1, 1, 4, 5, 1, 1, 3, 4, 1, 1, 5, 6, 1, 1, 3, 4, 1, 1, 4, 5, 1, 1, 3, 4, 1, 1, 6, 7, 1, 1, 3, 4, 1, 1, 4, 5, 1, 1, 3, 4, 1, 1, 5, 6, 1, 1, 3, 4, 1, 1, 4, 5, 1, 1, 3, 4, 1, 1, 7, 8, 1, 1, 3, 4, 1, 1, 4, 5, 1, 1, 3, 4, 1, 1, 5, 6, 1, 1, 3, 4, 1, 1, 4

Offset

2,3

Comments

In contrast to A158570, it is a non-periodic and unlimited sequence.

Links

Amiram Eldar, Table of n, a(n) for n = 2..10000

Formula

a(n)=1, if n==2,3,6,7 mod 8; a(n)=3, if n==4 mod 8; a(n)=4, if n==5 mod 8; a(n)=5, if n=1 mod 8; a(n)=A007814(2n), if n==0 mod 8.

Mathematica

a[n_] := IntegerExponent[((2 n - 1)!! - 1), 2]; Array[a, 100, 2] (* Amiram Eldar, Sep 13 2019 *)

Crossrefs

Cf. A007814, A001147, A158570.

Sequence in context: A016453 A238550 A275886 * A083532 A073366 A001086

Adjacent sequences: A158569 A158570 A158571 * A158573 A158574 A158575

Keyword

nonn

Author

Vladimir Shevelev, Mar 21 2009

Extensions

a(17) and a(33) corrected and more terms added by Amiram Eldar, Sep 13 2019

Status

approved