A027083 a(n) = A027082(n, n+2)

2, 6, 14, 28, 54, 102, 190, 352, 650, 1198, 2206, 4060, 7470, 13742, 25278, 46496, 85522, 157302, 289326, 532156, 978790, 1800278, 3311230, 6090304, 11201818, 20603358, 37895486, 69700668, 128199518, 235795678, 433695870

Offset

2,1

Links

Table of n, a(n) for n=2..32.

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

Formula

G.f.: (2x^2(1+x+x^2))/((1-x)(1-x-x^2-x^3)). Cf. A008937.

a(n) = A027024(n) + 1.

a(n) = A000213(n+3) -3. - R. J. Mathar, Jun 24 2020

Crossrefs

Cf. A008937, A027024, A027082.

Sequence in context: A033547 A050531 A290699 * A249665 A337106 A321027

Adjacent sequences: A027080 A027081 A027082 * A027084 A027085 A027086

Keyword

nonn,easy

Author

Clark Kimberling

Status

approved