OFFSET
1,2
COMMENTS
Does a(n+1)/a(n) tend to 1 as n tends to infinity? - Rémy Sigrist, Nov 11 2019
LINKS
Rémy Sigrist, Table of n, a(n) for n = 1..10000
Rémy Sigrist, PARI program for A328019
FORMULA
a(1) = 1; a(n + 1) = A092433(a(n)) for n > 0.
EXAMPLE
A328018 starts like this: 1, 2, 3, 4, 5, 6, 1, 8, 9, 10, 11, 12, 13, 2, 15, 16, 3, 18, 19, 20, 4, 22, 23, 24, 25, 26, 5, 6, 29, 30, 31, 32, 33, 34, 1, 36, 8, 38, 39, 40.
This has 1's in positions 1, 7 and 35. Therefore, 1, 7 and 35 are in the sequence.
MATHEMATICA
With[{s = Select[Range[10^6], Or[Mod[#, 7] == 0, DigitCount[#, 10, 7] > 0] &]}, Nest[Append[#, s[[#[[-1]] ]] ] &, {1}, 12]] (* Michael De Vlieger, Oct 17 2019 *)
PROG
(PARI) print1 (w=1", "); k=0; for (n=1, oo, if (n%7==0 || setsearch(Set(digits(n)), 7), if (w==k++, print1 (w=n", ")))) \\ Rémy Sigrist, Nov 11 2019
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rens Reus and David A. Corneth, Oct 01 2019
EXTENSIONS
More terms from Rémy Sigrist, Nov 11 2019
STATUS
approved