OFFSET
1,2
COMMENTS
All terms are 7-smooth (A002473).
This sequence is infinite as it contains the powers of 5.
LINKS
Rémy Sigrist, Table of n, a(n) for n = 1..10000
Rémy Sigrist, Illustration of terms < 1000
Rémy Sigrist, PARI program for A336580
EXAMPLE
Regarding the number 540:
- 540 / 4 = 135,
- 135 / 3 = 45,
- 45 / 5 = 9,
- 9 / 9 = 1,
- so A334676(540) = 1
- and 540 belongs to this sequence.
PROG
(PARI) for (n=1, #keep=vector(2500, n, n==1), if (keep[n], print1 (n ", "); for (d=2, min(9, #keep\n), if (setsearch (Set(digits(nd=n*d)), d), keep[nd]=1))))
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jul 26 2020
STATUS
approved