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A113770
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Partial sums of A113311(n)^2.
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2
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1, 10, 26, 42, 58, 74, 90, 106, 122, 138, 154, 170, 186, 202, 218, 234, 250, 266, 282, 298, 314, 330, 346, 362, 378, 394, 410, 426, 442, 458, 474, 490, 506, 522, 538, 554, 570, 586, 602, 618, 634, 650, 666, 682, 698, 714, 730, 746, 762, 778, 794
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Central coefficients of number triangle A115284.
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FORMULA
| G.f.: (1+8x+7x^2)/(1-x)^2; a(n)=7*0^n+2(8n-3); a(n)=sum{k=0..n, (4-C(1, k)-2*C(0, k))^2}; a(n)=A115284(2n, n).
a(0)=1, a(1)=10, a(2)=26, a(n)=2*a(n-1)-a(n-2) [From Harvey P. Dale, Aug 19 2011]
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MATHEMATICA
| Accumulate[CoefficientList[Series[(1+x)^2/(1-x), {x, 0, 110}], x]^2] (* or *) Join[{1}, LinearRecurrence[{2, -1}, {10, 26}, 110]] (* From Harvey P. Dale, Aug 19 2011 *)
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CROSSREFS
| Sequence in context: A044071 A186279 A054315 * A044452 A198017 A137351
Adjacent sequences: A113767 A113768 A113769 * A113771 A113772 A113773
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Jan 19 2006
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