OFFSET
1,1
COMMENTS
Contains only multiples of 5. Differs from A067761 by including for example 385 = 5*7*11, which is not present in A067761.
The asymptotic density of this sequence is 6 * Sum_{p prime, p == 1 (mod 6)} ((p-1)/(Product_{q prime, q <= p} q)) = 0.1738373091... . - Amiram Eldar, Dec 04 2022
FORMULA
{k | A053669(6*k) == 1 (mod 6)}.
EXAMPLE
35 is not present as 6*35 = 210 = 2*3*5*7, and the first nondividing prime is 11, which is of the form 6m+5, not of 6m+1.
385 is present as 6*385 = 2310 = 2*3*5*7*11, and the first nondividing prime is 13, which is of the form 6m+1.
MATHEMATICA
f[n_] := Module[{p = 2}, While[Divisible[n, p], p = NextPrime[p]]; p]; Select[Range[400], Mod[f[6*#], 6] == 1 &] (* Amiram Eldar, Dec 04 2022 *)
PROG
(PARI) isA358848(n) = !A358847(n);
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 03 2022
STATUS
approved