A109366 a(-1)=0, a(0)=1 and recursively a(n) = prime(n)*(a(n-1)+a(n-2)).

1, 2, 9, 55, 448, 5533, 77753, 1415862, 28378685, 685274581, 20695944714, 662817798145, 25290008485783, 1064065877641048, 46842303103453733, 2251599342111454707, 121817407196390147320, 7320071385771594519593

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Maple

A109366 := proc(n) if n<= 0 then n+1; else ithprime(n)*(procname(n-1)+procname(n-2)) ; end if; end proc:
seq(A109366(n), n=0..20) ; # R. J. Mathar, Sep 15 2011

Mathematica

nxt[{n_, a_, b_}]:={n+1, b, (a+b)Prime[n+1]}; NestList[nxt, {0, 0, 1}, 20][[;; , 2]] (* Harvey P. Dale, Aug 06 2025 *)

Crossrefs

Cf. A109365.

Sequence in context: A231172 A009363 A069564 * A303914 A241457 A229208

Adjacent sequences: A109363 A109364 A109365 * A109367 A109368 A109369

Keyword

nonn

Author

Giorgio Balzarotti, Aug 23 2005

Status

approved