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A236392
G.f.: (x+x^3+x^4)/(1-x-x^3-2*x^4).
0
0, 1, 1, 2, 4, 7, 11, 19, 34, 59, 100, 172, 299, 517, 889, 1532, 2647, 4570, 7880, 13591, 23455, 40475, 69826, 120463, 207848, 358624, 618739, 1067513, 1841833, 3177820, 5482811, 9459670, 16321156, 28159607, 48584899, 83825395, 144627314, 249531427, 430526620, 742804724, 1281590779, 2211180253, 3815038217, 6582238444, 11356600255
OFFSET
0,4
FORMULA
a(n) = a(n-1) + a(n-3) + 2*a(n-4), a(0) = 0, a(1) = 1, a(2) = 1, a(3) = 2, a(4) = 4. - Philippe Deléham, Jan 25 2014
CROSSREFS
Sequence in context: A192670 A118647 A000802 * A200377 A080005 A364590
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jan 24 2014
STATUS
approved