A139700 Binomial transform of [1, 30, 30, 30, ...].
1, 31, 91, 211, 451, 931, 1891, 3811, 7651, 15331, 30691, 61411, 122851, 245731, 491491, 983011, 1966051, 3932131, 7864291, 15728611, 31457251, 62914531, 125829091, 251658211, 503316451, 1006632931, 2013265891, 4026531811, 8053063651, 16106127331
Offset: 1
Examples
a(3) = 91 = (1, 2, 1) dot (1, 30, 30) = (1 + 60 + 30).
Links
- Index entries for linear recurrences with constant coefficients, signature (3,-2).
Programs
-
Maple
seq(30*2^(n-1)-29,n=1..27); # Emeric Deutsch, May 07 2008
-
Mathematica
LinearRecurrence[{3,-2},{1,31},30] (* Harvey P. Dale, Apr 18 2018 *)
-
PARI
Vec(x*(28*x+1)/((x-1)*(2*x-1)) + O(x^100)) \\ Colin Barker, Mar 11 2014
Formula
A007318 * [1, 30, 30, 30, ...].
a(n) = 30*2^(n-1) - 29. - Emeric Deutsch, May 07 2008
a(n) = 2*a(n-1) + 29 (with a(1)=1). - Vincenzo Librandi, Nov 24 2010
From Colin Barker, Mar 11 2014: (Start)
a(n) = 3*a(n-1) - 2*a(n-2).
G.f.: x*(28*x+1) / ((x-1)*(2*x-1)). (End)
Extensions
More terms from Emeric Deutsch, May 07 2008
More terms from Colin Barker, Mar 11 2014
Comments