A199213 a(n) = (3*5^n+1)/2.

2, 8, 38, 188, 938, 4688, 23438, 117188, 585938, 2929688, 14648438, 73242188, 366210938, 1831054688, 9155273438, 45776367188, 228881835938, 1144409179688, 5722045898438, 28610229492188, 143051147460938, 715255737304688

Offset: 0

Author

Vincenzo Librandi, Nov 04 2011

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (6,-5).

Crossrefs

Cf. A083065.

Programs

Magma

[(3*5^n+1)/2: n in [0..30]];

Formula

a(n) = 2*A083065(n).

a(n) = 5*a(n-1)-2.

a(n) = 6*a(n-1)-5*a(n-2).

G.f.: 2*(1-2*x)/((1-x)*(1-5*x)). - Bruno Berselli, Nov 04 2011