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A077952 Expansion of 1/(1-x+x^2+2*x^3). 1
1, 1, 0, -3, -5, -2, 9, 21, 16, -23, -81, -90, 37, 289, 432, 69, -941, -1874, -1071, 2685, 7504, 6961, -5913, -27882, -35891, 3817, 95472, 163437, 60331, -294050, -681255, -507867, 761488, 2631865, 2886111, -1268730, -9418571, -13922063, -1966032, 30793173, 60603331, 33742222, -88447455 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

Row sums of Riordan array (1,x(1-x-2x^2)). - Paul Barry (pbarry(AT)wit.ie), Mar 09 2006

LINKS

Index to sequences with linear recurrences with constant coefficients, signature (1,-1,-2). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 31 2010]

FORMULA

a(n)=sum{k=0..n, sum{j=0..n, C(k,j-k)C(k,n-j)(-2)^(n-j)}} - Paul Barry (pbarry(AT)wit.ie), Mar 09 2006

a(n) = (-1)^n*A077975(n). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 31 2010]

CROSSREFS

Sequence in context: A101157 A193725 * A077975 A112323 A102507 A076556

Adjacent sequences:  A077949 A077950 A077951 * A077953 A077954 A077955

KEYWORD

sign

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Nov 17 2002

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Last modified February 15 05:45 EST 2012. Contains 205694 sequences.