A038196 -id:A038196 - cp's OEIS frontend

A068587 Multiplicative 3-wave sequence starting with 1,2,3.

1, 2, 3, 6, 6, 36, 108, 3888, 23328, 90699264, 9795520512, 888446500935303168, 20725679973818752303104, 18413657852244156256526524022900467433472, 180371363192607497842938699938382286478962971377664

Offset: 0

Floor van Lamoen, Mar 21 2002

Cf. A038196.

For given n, this generates terms with index 0 through 2n: a[0] := 1; a[1] := 2; a[2] := 3; for i from 1 to n-1 do a[2*i+1] := a[2*i]*a[2*i-1]; a[2*i+2] := a[2*i+1]*a[2*i-2]; od; # Christopher N. Swanson (cswanson(AT)ashland.edu), Jul 22 2003

a(n)=a(n-1)*a(n-2) if n is odd, a(n)=a(n-1)*a(n-4) if n is even.

More terms from Christopher N. Swanson (cswanson(AT)ashland.edu), Jul 22 2003

A120771 Expansion of ( 1-x^3+x^4+x^5-x^8 ) / ( 1-2*x^3-x^6+x^9 ).

Original entry on oeis.org

1, 0, 0, 1, 1, 1, 3, 2, 1, 6, 5, 3, 14, 11, 6, 31, 25, 14, 70, 56, 31, 157, 126, 70, 353, 283, 157, 793, 636, 353, 1782, 1429, 793, 4004, 3211, 1782, 8997, 7215, 4004, 20216, 16212, 8997, 45425, 36428, 20216, 102069, 81853, 45425, 229347, 183922, 102069, 515338, 413269, 229347, 1157954, 928607, 515338

Offset: 0

Gary W. Adamson, Jul 03 2006

Index entries for linear recurrences with constant coefficients, signature (0,0,2,0,0,1,0,0,-1).

Cf. A077998 (trisection), A006054 (trisection), A006356 (trisection), A038196.

CoefficientList[Series[(1-x^3+x^4+x^5-x^8)/(1-2*x^3-x^6+x^9),{x,0,60}],x] (* or *) LinearRecurrence[{0,0,2,0,0,1,0,0,-1},{1,0,0,1,1,1,3,2,1},60] (* Harvey P. Dale, Feb 19 2016 *)

Three consecutive coefficients are generated from the left row of the n-th power of the matrix [1,1,1; 1,1,0; 1,0,0].

cp's OEIS Frontend

A068587 Multiplicative 3-wave sequence starting with 1,2,3.

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