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 A117374 Expansion of (1-3x)/(1-x^2+x^3). 2
 1, -3, 1, -4, 4, -5, 8, -9, 13, -17, 22, -30, 39, -52, 69, -91, 121, -160, 212, -281, 372, -493, 653, -865, 1146, -1518, 2011, -2664, 3529, -4675, 6193, -8204, 10868, -14397, 19072, -25265, 33469 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Diagonal sums of number triangle A117372. LINKS Index entries for linear recurrences with constant coefficients, signature (0,1,-1). FORMULA a(n)=a(n-2)+a(n-3); a(n)=sum{k=0..floor(n/2), (-1)^n*(C(k,n-2k)+3*C(k, n-2k-1))}. CROSSREFS Sequence in context: A260502 A014388 A186693 * A202142 A021322 A277129 Adjacent sequences:  A117371 A117372 A117373 * A117375 A117376 A117377 KEYWORD easy,sign AUTHOR Paul Barry, Mar 10 2006 STATUS approved

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Last modified December 6 11:48 EST 2021. Contains 349563 sequences. (Running on oeis4.)