A268610 Indices of records in A004290.

1, 2, 3, 6, 9, 18, 36, 72, 99, 198, 396, 792, 999, 1998, 3996, 7992, 9999, 10989, 19998, 21978, 39996, 43956, 76923, 99999, 199998

Offset

1,2

Comments

a(n+1) <= 2*a(n) for all n >= 2.

Links

Table of n, a(n) for n=1..25.

Example

6 is a term because A004290(n) < A004290(6) for all n < 6, where A004290(n) is the least positive multiple of n that when written in base 10 uses only 0's and 1's.

Prog

(PARI) lista(nn) = {my(k, r=0); for(n=1, nn, k=1; while(fromdigits(binary(k))%n>0, k++); if(k>r, r=k; print1(n, ", "))); } \\ Jinyuan Wang, May 16 2020; a(1)=0 inserted by Georg Fischer, Jun 24 2020; a(1)=0 removed again by David A. Corneth, Feb 19 2024

Crossrefs

Cf. A004290, A268609.

Sequence in context: A085431 A108862 A298413 * A018582 A018619 A018638

Adjacent sequences: A268607 A268608 A268609 * A268611 A268612 A268613

Keyword

nonn,base,more

Author

David Radcliffe, Feb 08 2016

Extensions

a(1)=0 inserted by Georg Fischer, Jun 24 2020

Initial 0 removed for consistency with change in A004290 by Sean A. Irvine, Feb 19 2024

Status

approved