A262602 a(n) = a(n-7) + a(n-4) + a(n-1) for n>1 and a(n)=1 for n<=1.

1, 1, 3, 5, 7, 9, 13, 19, 27, 39, 57, 83, 119, 171, 247, 357, 515, 743, 1073, 1549, 2235, 3225, 4655, 6719, 9697, 13995, 20199, 29153, 42075, 60725, 87643, 126493, 182563, 263487, 380283, 548851, 792139, 1143269, 1650045, 2381459, 3437085, 4960637, 7159533

Offset

0,3

Links

Table of n, a(n) for n=0..42.

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

Formula

a(n) = a(n-7) + a(n-4) + a(n-1) for n>1 and a(n)=1 for n<=1.

G.f.: (1+2*x^2+2*x^3+x^4+x^5+x^6) / (1-x-x^4-x^7). - Wesley Ivan Hurt, Oct 08 2015

Mathematica

LinearRecurrence[{1, 0, 0, 1, 0, 0, 1}, {1, 1, 3, 5, 7, 9, 13}, 50] (* or *) CoefficientList[Series[(1 + 2*x^2 + 2*x^3 + x^4 + x^5 + x^6)/(1 - x - x^4 - x^7), {x, 0, 50}], x] (* Wesley Ivan Hurt, Oct 08 2015 *)

Prog

(R) a<- (function(n) {if (n < 2) return(1); a(n-7) + a(n-4) +  a(n-1)})
(Magma) I:=[1, 3, 5, 7, 9, 13, 19]; [n le 7 select I[n] else Self(n-7)+Self(n-4)+Self(n-1): n in [1..40]]; // Vincenzo Librandi, Oct 09 2015

Crossrefs

Sequence in context: A121259 A211139 A089228 * A133847 A134180 A107220

Adjacent sequences: A262599 A262600 A262601 * A262603 A262604 A262605

Keyword

nonn,easy

Author

Tobias Kind, Sep 25 2015

Status

approved