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A131761
a(3n) = 3a(3n-1)-3a(3n-2)+2a(3n-3), a(3n+1) = 3a(3n)-3a(3n-1)+2a(3n-2), a(3n+2) = 3a(3n+1)-3a(3n), a(0) = 0, a(1) = 1, a(2) = 2.
1
0, 1, 2, 3, 5, 6, 9, 19, 30, 51, 101, 150, 249, 499, 750, 1251, 2501, 3750, 6249, 12499, 18750, 31251, 62501, 93750, 156249, 312499, 468750, 781251, 1562501, 2343750, 3906249, 7812499, 11718750, 19531251, 39062501, 58593750, 97656249, 195312499, 292968750
OFFSET
0,3
FORMULA
a(n) = a(n-1)-a(n-2)+5*a(n-3)-5*a(n-4)+5*a(n-5) for n>7. - Colin Barker, Nov 04 2014
G.f.: x*(x+1)*(4*x^5-2*x^4+3*x^3-2*x^2-1) / ((x^2-x+1)*(5*x^3-1)). - Colin Barker, Nov 04 2014
MATHEMATICA
LinearRecurrence[{1, -1, 5, -5, 5}, {0, 1, 2, 3, 5, 6, 9, 19}, 40] (* Harvey P. Dale, May 13 2022 *)
PROG
(PARI) concat(0, Vec(x*(x+1)*(4*x^5-2*x^4+3*x^3-2*x^2-1)/((x^2-x+1)*(5*x^3-1)) + O(x^100))) \\ Colin Barker, Nov 04 2014
CROSSREFS
Sequence in context: A124253 A256230 A079371 * A272776 A055690 A108861
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Oct 23 2007
EXTENSIONS
More terms from Colin Barker, Nov 04 2014
STATUS
approved