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A120957
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Sequence uniquely defined by: n*a(n) = (n-1)*[x^n] B(x) for n>1 with a(0)=a(1)=1, or, equivalently, x*A'(x) = 1+x - B(x) + x*B'(x), where B(x) = series_reversion(x/A(x))/x.
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1
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1, 1, 1, 8, 123, 3024, 106850, 5110440, 317955435, 24986363648, 2422868732514, 284385893015080, 39758967921029830, 6530586385172586528, 1245479442254732687652, 272988926352496428778928
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OFFSET
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0,4
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COMMENTS
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a(n) is divisible by (n-1) for n>1.
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LINKS
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FORMULA
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The g.f. of A120958 equals B(x) = series_reversion(x/A(x))/x, so that both A(x) = B(x/A(x)) and B(x) = A(x*B(x)) equivalently hold.
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PROG
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(PARI) {a(n)=local(A=[1, 1]); for(i=1, n, A=concat(A, 0); A[ #A]=(#A-2)*Vec(serreverse(x/Ser(A)))[ #A]); A[n+1]}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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