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A277298
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Central terms of triangle A277295 in odd-indexed rows; a(n) = A277295(2*n-1,n-1).
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4
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1, 2, 76, 5404, 535410, 66031704, 9583782716, 1584902128648, 292586323812088, 59462699504146980, 13171171610678351360, 3155802303880338506184, 813045290972961285049576, 224143228528852050484555760, 65850557807967931843625040120, 20543425063284611418233827507248, 6784261706348459523065200262509390
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OFFSET
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1,2
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COMMENTS
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G.f. G(x,y) of triangle A277295 satisfies:
(1) G(x,y) = x + G( y*G(x,y) + (1-y)*x, y)^2.
(2) G( x - y*G(x,y)^2, y) = x + (1-y)*G(x,y)^2.
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LINKS
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Table of n, a(n) for n=1..17.
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PROG
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(PARI) {A277295(n, k) = my(A=x); for(i=1, n, A = x + subst(A^2, x, y*A + (1-y)*x +x*O(x^n)) ); polcoeff(polcoeff(A, n, x), k, y)}
for(n=1, 20, print1(A277295(2*n-1, n-1), ", "))
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CROSSREFS
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Cf. A277295, A277296, A277297, A277299.
Sequence in context: A198623 A198651 A198658 * A087287 A349066 A266877
Adjacent sequences: A277295 A277296 A277297 * A277299 A277300 A277301
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna, Oct 11 2016
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STATUS
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approved
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