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A160637 Hankel transform of A114464(n+1). 2
1, 1, -2, -8, -32, -128, 1024, 16384, 262144, 4194304, -134217728, -8589934592, -549755813888, -35184372088832, 4503599627370496, 1152921504606846976, 295147905179352825856, 75557863725914323419136 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Hankel transform of A114464(n) is A160636.

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..114

FORMULA

a(n) = (-2)^floor(C(n+1,2)/2).

MATHEMATICA

Table[(-2)^Floor[Binomial[n + 1, 2]/2], {n, 0, 50}] (* G. C. Greubel, May 03 2018 *)

PROG

(PARI) for(n=0, 50, print1((-2)^floor(binomial(n+1, 2)/2), ", ")) \\ G. C. Greubel, May 03 2018

(MAGMA) [(-2)^Floor(Binomial(n+1, 2)/2): n in [0..50]]; // G. C. Greubel, May 03 2018

CROSSREFS

Sequence in context: A081294 A004171 A009117 * A183895 A228921 A150829

Adjacent sequences:  A160634 A160635 A160636 * A160638 A160639 A160640

KEYWORD

easy,sign

AUTHOR

Paul Barry, May 21 2009

STATUS

approved

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Last modified August 17 03:29 EDT 2018. Contains 313810 sequences. (Running on oeis4.)