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A094015 Expansion of (1+4x)/(1-8x^2). 7
1, 4, 8, 32, 64, 256, 512, 2048, 4096, 16384, 32768, 131072, 262144, 1048576, 2097152, 8388608, 16777216, 67108864, 134217728, 536870912, 1073741824, 4294967296, 8589934592, 34359738368, 68719476736, 274877906944 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Row sums of triangle A135838 - Gary W. Adamson, Dec 01 2007

Row sums of triangle A152842. - Reinhard Zumkeller, May 01 2014

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000

Index to divisibility sequences

Index entries for linear recurrences with constant coefficients, signature (0,8).

FORMULA

a(n)=2^(3n/2)(1+sqrt(2)+(1-sqrt(2))(-1)^n)/2

a(n)=(1/4)(3+(-1)^n)8^floor((n+1)/2) - Paul Barry, Jul 14 2004

a(n)=(1+sqrt(2))(2sqrt(2))^n/2+(1-sqrt(2))(-2sqrt(2))^n/2. Third binomial transform is A002315 (NSW numbers). - Paul Barry, Jul 17 2004

a(n)=2^A007494(n). - Paul Barry, Aug 18 2007

a(n)=A016116(n+1)*A000079(n). [From R. J. Mathar, Jul 08 2009]

a(n+3) = a(n+2)*a(n+1)/a(n). [Reinhard Zumkeller, Mar 04 2011]

MAPLE

a:=n->mul(3-(-1)^j, j=1..n):seq(a(n), n=0..25); # [From Zerinvary Lajos, Dec 13 2008]

PROG

(Haskell)

a094015 = sum . a152842_row  -- Reinhard Zumkeller, May 01 2014

CROSSREFS

Cf. A094014, A135838.

Sequence in context: A034041 A050442 A229953 * A094867 A149093 A149094

Adjacent sequences:  A094012 A094013 A094014 * A094016 A094017 A094018

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Apr 21 2004

STATUS

approved

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Last modified March 28 02:40 EDT 2017. Contains 284182 sequences.