A358848 Numbers k for which A053669(6*k) [the smallest prime not dividing 6k] is of the form 6m+1.
5, 10, 15, 20, 25, 30, 40, 45, 50, 55, 60, 65, 75, 80, 85, 90, 95, 100, 110, 115, 120, 125, 130, 135, 145, 150, 155, 160, 165, 170, 180, 185, 190, 195, 200, 205, 215, 220, 225, 230, 235, 240, 250, 255, 260, 265, 270, 275, 285, 290, 295, 300, 305, 310, 320, 325, 330, 335, 340, 345, 355, 360, 365, 370, 375, 380, 385
Offset: 1
Keywords
Examples
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.
Crossrefs
Programs
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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 *) -
PARI
isA358848(n) = !A358847(n);
Formula
{k | A053669(6*k) == 1 (mod 6)}.
Comments