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A144433 Multiples of 8 interleaved with a sequence of odd numbers. 8
8, 3, 16, 5, 24, 7, 32, 9, 40, 11, 48, 13, 56, 15, 64, 17, 72, 19, 80, 21, 88, 23, 96, 25, 104, 27, 112, 29, 120, 31, 128, 33, 136, 35, 144, 37, 152, 39, 160, 41, 168, 43, 176, 45, 184, 47, 192, 49, 200, 51, 208, 53, 216, 55, 224, 57, 232, 59, 240, 61, 248, 63, 256, 65, 264 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For n >= 2, these are the numerators of 1/n^2 - 1/(n+1)^2: A061037(4), A061039(5), A061041(6), A061043(7), A061045(8), A061047(9), A061049(10), etc.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..5000

FORMULA

a(2n+1) = A008590(n+1), a(2n) = A005408(n).

a(2n+1)+a(2n+2) = A017281(n+1).

From R. J. Mathar, Apr 01 2009: (Start)

a(n) = 2*a(n-2) - a(n-4).

G.f.: x*(8+3*x-x^3)/((1-x)^2*(1+x)^2). (End)

a(n) = 5+3/2*(-1)^(n-1)*(n-1)+3*(-1)^(n-1)+5/2*(n-1). - Paolo P. Lava, Apr 06 2009

a(n) = (n + 1) * 4^(n mod 2). - Wesley Ivan Hurt, Nov 27 2013

MAPLE

A144433:=n->(n+1)*4^(n mod 2); seq(A144433(n), n=1..100); # Wesley Ivan Hurt, Nov 27 2013

MATHEMATICA

Table[(n + 1)* 4^Mod[n, 2], {n, 100}] (* Wesley Ivan Hurt, Nov 27 2013 *)

PROG

(MAGMA) [5+3/2*(-1)^(n-1)*(n-1)+3*(-1)^(n-1)+5/2*(n-1): n in [1..70]]; // Vincenzo Librandi, Jul 30 2011

(PARI) x='x+O('x^50); Vec( x*(8+3*x-x^3)/((1-x)^2*(1+x)^2)) \\ G. C. Greubel, Sep 19 2018

CROSSREFS

Cf. A120070.

Sequence in context: A070608 A070486 A195161 * A274401 A228691 A228313

Adjacent sequences:  A144430 A144431 A144432 * A144434 A144435 A144436

KEYWORD

nonn,easy

AUTHOR

Paul Curtz, Oct 04 2008

EXTENSIONS

Edited by R. J. Mathar, Apr 01 2009

STATUS

approved

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Last modified August 20 14:06 EDT 2019. Contains 326152 sequences. (Running on oeis4.)