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A126948
The sequence d[n] defined in A126940.
2
0, 0, 4, 12, 34, 110, 354, 1120, 3552, 11290, 35862, 113884, 361702, 1148810, 3648670, 11588338, 36805222, 116895404, 371266018, 1179160836, 3745078428, 11894570660, 37777796510, 119984315496, 381076645196, 1210319938646, 3844041278068, 12208882029838
OFFSET
0,3
COMMENTS
Linear recurrence and empirical g.f confirmed for more terms. - Ray Chandler, Mar 07 2024
FORMULA
Empirical g.f.: -2*x^2*(x^3+3*x^2+2*x+2) / (x^6+4*x^5+4*x^4+7*x^3+x^2+2*x-1). - Colin Barker, Apr 08 2013
MATHEMATICA
LinearRecurrence[{2, 1, 7, 4, 4, 1}, {0, 0, 4, 12, 34, 110}, 40] (* Harvey P. Dale, Apr 15 2024 *)
CROSSREFS
Sequence in context: A077994 A077843 A061703 * A131593 A340492 A084362
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Mar 18 2007
STATUS
approved