A380536 a(n) = 1 if n is a multiple of A351566(n), otherwise 0, where A351566 is the radix prime of the second least significant nonzero digit in the primorial base expansion of n, or 1 if there is no such digit.

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

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions.

Index entries for sequences related to primorial base.

Prog

(PARI)
A351566(n) = { my(p=2, c=0); while(n, if((n%p)>0, c++; if(2==c, return(p))); n = n\p; p = nextprime(1+p)); (1); };
A380536(n) = !(n%A351566(n));

Crossrefs

Characteristic function of A380537, whose complement A380538 gives the positions of 0's.

Cf. A049345, A351566.

Sequence in context: A181650 A115952 A115524 * A370122 A117198 A379968

Adjacent sequences: A380533 A380534 A380535 * A380537 A380538 A380539

Keyword

nonn,new

Author

Antti Karttunen, Feb 12 2025

Status

approved