A236392 G.f.: (x+x^3+x^4)/(1-x-x^3-2*x^4).

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

Links

Table of n, a(n) for n=0..44.

A. O. Munagi, J. A. Sellers, Some inplace identities for integer compositions, 2013.

Index entries for linear recurrences with constant coefficients, signature (1,0,1,2).

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

Adjacent sequences: A236389 A236390 A236391 * A236393 A236394 A236395

Keyword

nonn,easy

Author

N. J. A. Sloane, Jan 24 2014

Status

approved