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, 399996, 729927, 999999

Offset: 1

Author

David Radcliffe, Feb 08 2016

Keywords

• nonn
• base
• more

Comments

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

Examples

			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.
		

Crossrefs

Cf. A004290, A268609.

Programs

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

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

a(26)-a(28) from David Radcliffe, Aug 02 2025