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A341549
a(n) = Sum_{k=1..n} (-1)^(n+k)*A087322(n,k).
0
3, 6, 23, 50, 131, 294, 687, 1530, 3419, 7502, 16391, 35490, 76467, 163830, 349535, 742730, 1572875, 3320478, 6990519, 14680050, 30758243, 64312646, 134217743, 279620250, 581610171, 1207959534, 2505397607, 5189752130, 10737418259, 22190664342
OFFSET
1,1
FORMULA
a(n) = ((n + 1)*2^(n + 2) - 3 + (4*n + 1)*(-1)^(n + 1))/6.
G.f.: (4*x^3 - 2*x^2 + 3*x - 3)*x/((-1 + 2*x)^2*(-1 + x)*(1 + x)^2).
CROSSREFS
Cf. A087322.
Sequence in context: A090910 A256674 A176424 * A151443 A148643 A240646
KEYWORD
nonn,easy
AUTHOR
Petros Hadjicostas, Feb 15 2021
STATUS
approved