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A097114
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Expansion of (1+8x-42x^2-392x^3)/(1-99x^2+2450x^4).
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0
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1, 8, 57, 400, 3193, 20000, 176457, 1000000, 9646393, 50000000, 522673257, 2500000000, 28110989593, 125000000000, 1502438490057, 6250000000000, 79869486012793, 312500000000000, 4226104814626857, 15625000000000000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| G.f. : 8(1+x)/(1-50x^2)-7/(1-49x^2); a(n)=99a(n-2)-2450a(n-4); a(n)=(4+2sqrt(50)/25)(sqrt(50))^n+(4-2sqrt(50)/25)(-sqrt(50))^n-7^(n+1)(1+(-1)^n)/2 a(n)=sum{k=0..n, binomial(floor(n/2), floor(k/2))7^k }.
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CROSSREFS
| Sequence in context: A108666 A164031 A023000 * A022038 A015453 A181246
Adjacent sequences: A097111 A097112 A097113 * A097115 A097116 A097117
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Jul 25 2004
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