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A107104
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Absolute row sums of triangle A107102, which is the matrix inverse of A100862.
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2
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1, 2, 6, 26, 154, 1182, 11254, 128522, 1715802, 26251118, 453132214, 8714516538, 184817376154, 4285657717694, 107880712446966, 2929921866938858, 85399256991014746, 2659096654189212558, 88091786616208073398
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| a(n) = 2*A043301(n-1) = 2^n*Sum_{k=0..n-1}(n+k-1)!/(n-k-1)!/k!/4^k for n>0, with a(0) = 1.
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PROG
| (PARI) a(n)=if(n==0, 1, 2^n*sum(k=0, n-1, (n+k-1)!/(n-k-1)!/k!/4^k)) (PARI) {a(n)=local(X=x+x*O(x^n), Y=y+y*O(y^n)); sum(k=0, n, abs((matrix(n+1, n+1, m, j, if(m>=j, (m-1)!*polcoeff(polcoeff(exp(X+Y*X^2/2+X*Y), m-1, x), j-1, y)))^-1)[n+1, k+1]))}
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CROSSREFS
| Cf. A100862, A043301, A107102, A107103.
Sequence in context: A159602 A032271 A205502 * A141761 A123306 A099758
Adjacent sequences: A107101 A107102 A107103 * A107105 A107106 A107107
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KEYWORD
| nonn
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AUTHOR
| Paul D. Hanna (pauldhanna(AT)juno.com), May 21 2005
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