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A122997 Pentanacci numbers for following initial values: a[0] = 1; a[1] = -1; a[2] = 1; a[3] = -1; a[4] = 1;. 1
1, -1, 1, -1, 1, 1, 1, 3, 5, 11, 21, 41, 81, 159, 313, 615, 1209, 2377, 4673, 9187, 18061, 35507, 69805, 137233, 269793, 530399, 1042737, 2049967, 4030129, 7923025, 15576257, 30622115, 60201493, 118353019, 232675909, 457428793, 899281329, 1767940543, 3475679593, 6833006167, 13433336425 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,8

LINKS

Table of n, a(n) for n=1..41.

Index entries for linear recurrences with constant coefficients, signature (1,1,1,1,1).

FORMULA

a(n) = a(n - 1) + a(n - 2) + a(n - 3) + a(n - 4) + a(n - 5);

G.f.: (-1-x^4+2*x^3-x^2+2*x)/(-1+x^5+x^4+x^3+x^2+x). [Maksym Voznyy (voznyy(AT)mail.ru), Aug 12 2009]

MATHEMATICA

a[n_] := a[n] = a[n - 1] + a[n - 2] + a[n - 3] + a[n - 4] + a[n - 5]; a[0] = 1; a[1] = -1; a[2] = 1; a[3] = -1; a[4] = 1; Table[a[n], {n, 0, 50}]

CROSSREFS

Cf. A001591.

Sequence in context: A146787 A147243 A192664 * A146042 A291219 A284358

Adjacent sequences:  A122994 A122995 A122996 * A122998 A122999 A123000

KEYWORD

sign

AUTHOR

Artur Jasinski, Oct 28 2006

STATUS

approved

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Last modified October 27 19:26 EDT 2020. Contains 338035 sequences. (Running on oeis4.)