A192811 a(n) = A192809(n)/2.

0, 0, 1, 7, 37, 183, 893, 4351, 21205, 103367, 503917, 2456655, 11976517, 58387095, 284644701, 1387679903, 6765119669, 32980836455, 160785858381, 783851928559, 3821379890981, 18629722961207, 90822317465149, 442770585849407

Offset: 0

Author

Clark Kimberling, Jul 10 2011

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (7,-12,8).

Crossrefs

Cf. A192232, A192744, A192809.

Programs

GAP

a:=[0,0,1];; for n in [4..25] do a[n]:=7*a[n-1]-12*a[n-2]+8*a[n-3]; od; Print(a); # Muniru A Asiru, Jan 03 2019

Magma

m:=30; R:=PowerSeriesRing(Integers(), m); [0,0] cat Coefficients(R!( x^2/(1-7*x+12*x^2-8*x^3) )); // G. C. Greubel, Jan 03 2019

Mathematica

(See A192808.)
LinearRecurrence[{7,-12,8},{0,0,1},30] (* Harvey P. Dale, Dec 06 2018 *)

PARI

my(x='x+O('x^30)); concat([0,0], Vec(x^2/(1-7*x+12*x^2-8*x^3))) \\ G. C. Greubel, Jan 03 2019

Sage

(x^2/(1-7*x+12*x^2-8*x^3)).series(x, 30).coefficients(x, sparse=False) # G. C. Greubel, Jan 03 2019

Formula

a(n) = 7*a(n-1) - 12*a(n-2) + 8*a(n-3).

G.f.: x^2/(1-7*x+12*x^2-8*x^3). - Colin Barker, Jul 26 2012

Extensions

Name corrected by Colin Barker, Jul 26 2012