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Search: id:A104970
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| A104970 |
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Sum of squares of terms in even-indexed rows of triangle A104967. |
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+0
2
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| 1, 6, 18, 92, 298, 1444, 4852, 22840, 78490, 362580, 1265564, 5767688, 20366596, 91866984, 327351336, 1464522864, 5257011066, 23361650484, 84371466636, 372831130344, 1353477992556, 5952169844664, 21704580414936, 95051752387344
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OFFSET
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0,2
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COMMENT
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Sum of squares of terms in odd-indexed rows of triangle A104967 equals twice this sequence.
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FORMULA
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G.f. A(x) satisfies: 2*(1+12*x)*A(x) - (1-16*x^2)*deriv(A(x), x) + 4 = 0.
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PROGRAM
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(PARI) {a(n)=local(X=x+x*O(x^(2*n))); sum(k=0, 2*n, polcoeff(polcoeff((1-2*X)/(1-X-X*y*(1-2*X)), 2*n, x), k, y)^2)}
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CROSSREFS
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Cf. A104967, A104969.
Adjacent sequences: A104967 A104968 A104969 this_sequence A104971 A104972 A104973
Sequence in context: A129790 A121156 A057051 this_sequence A151470 A009573 A052655
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Mar 30 2005
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