A009518 -id:A009518 - cp's OEIS frontend

A012387 Duplicate of A009518.

0, 2, 16, 152, -5504, -1107808, -155757824, -22741022848, -3557729644544

Offset: 0

dead

A093051 Exponent of 2 in (3^n-3)*2^n.

0, 1, 4, 3, 7, 5, 8, 7, 12, 9, 12, 11, 15, 13, 16, 15, 21, 17, 20, 19, 23, 21, 24, 23, 28, 25, 28, 27, 31, 29, 32, 31, 38, 33, 36, 35, 39, 37, 40, 39, 44, 41, 44, 43, 47, 45, 48, 47, 53, 49, 52, 51, 55, 53, 56, 55, 60, 57, 60, 59, 63, 61, 64, 63, 71, 65, 68, 67, 71

Offset: 0

Ralf Stephan, Mar 16 2004

nonn

a(n) is the exponent of 2 in A009613(n), A010043(n), A010046(n), A012388(n-1), A009518(n), A012391(n-1), A012457(n-1), A012458(n-1), A012461(n-1), A012462(n-2).

Cf. A093050, A093052, A090740.

a(n)=if(n<1,0,if(n%2==0,a(n/2)+2*floor((n+2)/4)+1,n))

Recurrence: a(2n) = a(n) + [(n+1)/2] + 1, a(2n+1) = 2n+1.

a(n) = A090740(n) + n - 1, for n >= 1. - Amiram Eldar, Sep 14 2024

A024281 Expansion of sin(tan(x)^2)/2.

Original entry on oeis.org

0, 1, 8, 76, -2752, -553904, -77878912, -11370511424, -1778864822272, -282582967817984, -36606453394757632, 2075368674171759616, 5791517230149348343808, 4398620127304280971595776

Offset: 0

R. H. Hardin

sign

Cf. A009518.

With[{nn=30},Take[CoefficientList[Series[Sin[Tan[x]^2]/2,{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* Harvey P. Dale, Feb 12 2016 *)

Extended with signs Mar 1997

Prior Mathematica program replaced by Harvey P. Dale, Feb 12 2016

cp's OEIS Frontend

A012387 Duplicate of A009518.

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A093051 Exponent of 2 in (3^n-3)*2^n.

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A024281 Expansion of sin(tan(x)^2)/2.

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