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A174619 a(n) = A174618(n)+A174618(n+1). 0
1, 1, 1, 2, 2, 3, 3, 4, 5, 6, 8, 10, 13, 17, 21, 28, 34, 45, 55, 72, 89, 116, 144, 188, 233, 305, 377, 494, 610, 799, 987, 1292, 1597, 2090, 2584 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..35.

Index to sequences with linear recurrences with constant coefficients, signature (0,2,0,-1,0,0,0,1).

FORMULA

a(2n) = A024490(n+1). a(2n+1)= A000045(n+1).

a(n)= +2*a(n-2) -a(n-4) +a(n-8). G.f. -x*(1+x)*(x^3-x^2+1) / ( (x^4-x^2+1)*(x^4+x^2-1) ). - R. J. Mathar, Jan 27 2011

CROSSREFS

Cf. A024490, A000045

Sequence in context: A120160 A017980 A064650 * A130083 A117357 A029020

Adjacent sequences:  A174616 A174617 A174618 * A174620 A174621 A174622

KEYWORD

nonn,easy

AUTHOR

M. Dols (markdols99(AT)yahoo.com), Mar 23 2010

STATUS

approved

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Last modified November 27 04:47 EST 2014. Contains 250155 sequences.