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Search: id:A107592
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| A107592 |
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G.f. satisfies: A(x)^2 = Sum_{n>=0} x^n * A(x)^((n+1)*(n+2)/2). |
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+0
5
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| 1, 1, 3, 13, 67, 382, 2327, 14855, 98208, 667180, 4632647, 32751382, 235072482, 1709232902, 12568852562, 93348649555, 699485096637, 5283685539096, 40205412111227, 308020225286402, 2374795521493354, 18419175004781334
(list; graph; listen)
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OFFSET
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0,3
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FORMULA
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G.f. A(x)^2 = (1/x)*series-reversion(x/G107590(x)^2) and thus A(x) = G107590(x*A(x)^2) where G107590(x) is the g.f. of A107590. G.f. A(x) = (1/x)*series-reversion(x/G107591(x)) and thus A(x) = G107591(x*A(x)) where G107591(x) is the g.f. of A107591.
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EXAMPLE
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A^2 = A + x*A^3 + x^2*A^6 + x^3*A^10 + x^4*A^15 + x^5*A^21 ...
= (1 + x + 3*x^2 + 13*x^3 + 67*x^4 + 382*x^5 + 2327*x^6 +...)
+ (x + 3*x^2 + 12*x^3 + 58*x^4 + 315*x^5 + 1848*x^6 +...)
+ (x^2 + 6*x^3 + 33*x^4 + 188*x^5 + 1122*x^6 +...)
+ (x^3 + 10*x^4 + 75*x^5 + 520*x^6 +...)
+ (x^4 + 15*x^5 + 150*x^6 +...) +...
= 1 + 2*x + 7*x^2 + 32*x^3 + 169*x^4 + 976*x^5 + 5989*x^6 +...
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PROGRAM
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(PARI) {a(n)=local(A=1+x+x*O(x^n)); for(k=1, n, A=1+sum(j=1, n, x^j*A^((j+1)*(j+2)/2-1)+x*O(x^n))); polcoeff(A, n)}
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CROSSREFS
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Cf. A107590, A107591, A107593 (self-convolution).
Adjacent sequences: A107589 A107590 A107591 this_sequence A107593 A107594 A107595
Sequence in context: A062992 A064062 A114191 this_sequence A028418 A080832 A020017
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KEYWORD
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eigen,nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), May 17 2005
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