A296209 a(n) = 1 if n is a pentanacci number, 0 otherwise; characteristic function for A001591.

1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1

Offset

0

Links

Antti Karttunen, Table of n, a(n) for n = 0..65537

Index entries for characteristic functions

Mathematica

With[{pn=LinearRecurrence[{1, 1, 1, 1, 1}, {0, 0, 0, 0, 1}, 15]}, Table[ If[ MemberQ[ pn, n], 1, 0], {n, 0, 150}]] (* Harvey P. Dale, Aug 08 2021 *)

Prog

(PARI) A296209(n) = { if(n<=1, return(1)); my(p0=0, p1=0, p2=0, p3=1, p4=1, old_p0); while(n>p4, old_p0=p0; p0=p1; p1=p2; p2=p3; p3=p4; p4=old_p0+p0+p1+p2+p3; ); (n==p4); }
(Scheme)
(define (A296209 n) (let loop ((i 3)) (if (< (A001591 i) n) (loop (+ 1 i)) (if (= (A001591 i) n) 1 0))))
;; This uses memoization-macro definec:
(definec (A001591 n) (cond ((<= n 3) 0) ((= 4 n) 1) (else (+ (A001591 (- n 1)) (A001591 (- n 2)) (A001591 (- n 3)) (A001591 (- n 4)) (A001591 (- n 5))))))

Crossrefs

Cf. A001591, A288120.

Cf. also A010056, A102460, A147612, A294878.

Sequence in context: A266178 A339653 A255738 * A076141 A011751 A341540

Adjacent sequences: A296206 A296207 A296208 * A296210 A296211 A296212

Keyword

nonn

Author

Antti Karttunen, Dec 22 2017

Status

approved