login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A328840
Numbers with no digit 1 in their primorial base expansion (A049345).
5
0, 4, 12, 16, 18, 22, 24, 28, 60, 64, 72, 76, 78, 82, 84, 88, 90, 94, 102, 106, 108, 112, 114, 118, 120, 124, 132, 136, 138, 142, 144, 148, 150, 154, 162, 166, 168, 172, 174, 178, 180, 184, 192, 196, 198, 202, 204, 208, 420, 424, 432, 436, 438, 442, 444, 448, 480, 484, 492, 496, 498, 502, 504, 508, 510, 514, 522, 526
OFFSET
1,2
COMMENTS
Numbers for which the least missing nonzero digit (A329028) in their primorial base expansion is 1.
MATHEMATICA
q[n_] := Module[{k = n, p = 2, s = {}, r}, While[{k, r} = QuotientRemainder[k, p]; k != 0 || r != 0, AppendTo[s, r]; p = NextPrime[p]]; FreeQ[s, 1]]; Select[Range[0, 600], q] (* Amiram Eldar, Mar 06 2024 *)
PROG
(PARI)
A329028(n) = { my(m=Map(), p=2); while(n, mapput(m, (n%p), 1); n = n\p; p = nextprime(1+p)); for(k=1, oo, if(!mapisdefined(m, k), return(k))); };
isA328840(n) = (1 == A329028(n));
CROSSREFS
Cf. A049345.
Positions of ones in A329028.
Cf. also A328574 and A329027.
Cf. A255411 for an analogous sequence.
Sequence in context: A119622 A367909 A280892 * A255411 A340929 A067575
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Nov 07 2019
STATUS
approved