OFFSET
1,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (4,0,1,-4).
FORMULA
G.f.: x*(1+2*x+2*x^2) / ( (x-1)*(4*x-1)*(1+x+x^2) ). - R. J. Mathar, Apr 30 2015
a(1)=1, a(2)=6, a(3)=26, a(4)=105, a(n)=4*a(n-1)+a(n-3)-4*a(n-4). - Harvey P. Dale, May 22 2015
MATHEMATICA
Module[{nn=30, c}, c=PadRight[{}, nn, {1, 2, 2}]; Table[FromDigits[Take[c, n], 4], {n, nn}]] (* or *) LinearRecurrence[{4, 0, 1, -4}, {1, 6, 26, 105}, 30] (* Harvey P. Dale, May 22 2015 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved