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A154383 Powers of 4 at even indices, two times powers of 4 at odd indices. 3
1, 0, 4, 2, 16, 8, 64, 32, 256, 128, 1024, 512, 4096, 2048, 16384, 8192, 65536, 32768, 262144, 131072, 1048576, 524288, 4194304, 2097152, 16777216, 8388608, 67108864, 33554432, 268435456, 134217728, 1073741824, 536870912, 4294967296, 2147483648, 17179869184, 8589934592, 68719476736, 34359738368, 274877906944 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0,4).

FORMULA

a(2n) = A131577(2n+1); a(2n+1) = A131577(2n) (Consecutive terms of A131577 swapped).

a(2n) = A000302(n); a(2n+1) = A000302(n)/2, n>0.

a(n) = 4*a(n-2), n>3.

a(2n+1) = a(2n)/2, n>0.

G.f.: (1 + 2*x^3)/((1-2*x)*(2*x+1)). - R. J. Mathar, May 21 2009

a(n) = (5 + 3*(-1)^n)*2^(n-3), n>1. - R. J. Mathar, May 21 2009

E.g.f.: (1/4)*(-2*x + sinh(2*x) + 4*cosh(2*x)). - G. C. Greubel, Sep 15 2016

MATHEMATICA

Join[{1, 0}, Table[(5 + 3*(-1)^n)*2^(n - 3), {n, 2, 20}]] (* G. C. Greubel, Sep 15 2016 *)

PROG

(Magma) [1, 0] cat [(5+3*(-1)^n)*2^(n-3): n in [2..40]]; // Vincenzo Librandi, Sep 16 2016

CROSSREFS

Sequence in context: A348685 A110485 A240988 * A022664 A316463 A167784

Adjacent sequences: A154380 A154381 A154382 * A154384 A154385 A154386

KEYWORD

nonn,easy

AUTHOR

Paul Curtz, Jan 08 2009

EXTENSIONS

Edited by R. J. Mathar, May 21 2009

STATUS

approved

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Last modified November 30 02:32 EST 2022. Contains 358431 sequences. (Running on oeis4.)