A191597 Expansion of x*(1+3*x)/ ( (1-4*x)*(1+x+x^2)).
0, 1, 6, 21, 85, 342, 1365, 5461, 21846, 87381, 349525, 1398102, 5592405, 22369621, 89478486, 357913941, 1431655765, 5726623062, 22906492245, 91625968981, 366503875926, 1466015503701, 5864062014805, 23456248059222, 93824992236885, 375299968947541
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (3,3,4).
Programs
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Maple
A061347 := proc(n) op(1+(n mod 3),[-2,1,1]) ; end proc: A191597 := proc(n) (4^n-A061347(n+1))/3 ; end proc: seq(A191597(n),n=0..30) ; # R. J. Mathar, Jun 08 2011
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PARI
a(n)=([0,1,0; 0,0,1; 4,3,3]^n*[0;1;6])[1,1] \\ Charles R Greathouse IV, Jul 06 2017
Comments