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A164976 Triangle read by rows, expansion of 1/(1-2*y*x-x+x^2-y*x^2). 2

%I #26 Oct 15 2023 14:26:35

%S 1,1,2,0,5,4,-1,4,16,8,-1,-3,25,44,16,0,-10,7,102,112,32,1,-8,-41,97,

%T 344,272,64,1,4,-74,-80,528,1040,640,128,0,15,-33,-366,121,2168,2928,

%U 1472,256,-1,12,75,-426,-1219,1898,7664,7840,3328,512

%N Triangle read by rows, expansion of 1/(1-2*y*x-x+x^2-y*x^2).

%C Leftmost column is A010892.

%C Rows sum up to A000244 and diagonals to A000073.

%C A164975 has a similar g.f.: x/(1-2*y*x-x-x^2+y*x^2).. - _Georg Fischer_, Oct 15 2023

%H Georg Fischer, <a href="/A164976/b164976.txt">Table of n, a(n) for n = 1..5050</a>

%e Triangle begins:

%e 1;

%e 1, 2;

%e 0, 5, 4;

%e -1, 4, 16, 8;

%e -1, -3, 25, 44, 16;

%e 0, -10, 7, 102, 112, 32;

%e 1, -8, -41, 97, 344, 272, 64;

%e ...

%p s := 1/(1-2*y*x-x+x^2-y*x^2): t := series(s, x, 12):

%p seq(print(seq(coeff(coeff(t, x, n), y, m), m=0..n)), n=0..11); # _Georg Fischer_, Oct 15 2023

%Y Cf. A164975, A000244, A000045, A164965, A000073.

%Y Cf. A010892 (1st column), A000079 (right diagonal).

%K tabl,sign

%O 0,3

%A _Mark Dols_, Sep 03 2009

%E Missing commas inserted in what used to be the term "1-8-41" (now "1,-8,-41") by Geoff Bailey (geoff(AT)maths.usyd.edu.au), Nov 30 2009

%E Definition changed by _Georg Fischer_, Oct 15 2023

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Last modified April 16 14:51 EDT 2024. Contains 371749 sequences. (Running on oeis4.)