A238055 a(n) = (13*3^n-1)/2.

6, 19, 58, 175, 526, 1579, 4738, 14215, 42646, 127939, 383818, 1151455, 3454366, 10363099, 31089298, 93267895, 279803686, 839411059, 2518233178, 7554699535, 22664098606, 67992295819, 203976887458, 611930662375, 1835791987126, 5507375961379, 16522127884138

Offset: 0

Author

Philippe Deléham, Feb 17 2014

Keywords

• nonn
• easy

Examples

			Ternary....................Decimal
20...............................6
201.............................19
2011............................58
20111..........................175
201111.........................526
2011111.......................1579
20111111......................4738
201111111....................14215, etc.
		

Links

• Index entries for linear recurrences with constant coefficients, signature (4,-3).

Crossrefs

Cf. A000244, A003462, A052909, A060816, A237930.

Formula

a(n) = 3*a(n-1) + 1, a(0)=6.

a(n) = 4*a(n-1) - 3*a(n-2), a(0)=6, a(1)=19.

a(n) = 2*A237930(n) - A003462(n).

a(n) = A052909(n+1) + A000244(n).

a(n) = A237930(n) + A000244(n+1).

a(n) = 13*A003462(n) + 6.

G.f.: (6-5*x)/((1-x)*(1-3*x)).

E.g.f.: exp(x)*(13*exp(2*x) - 1)/2. - Stefano Spezia, Aug 28 2023