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A052424 Numbers k with no single-digit factors (apart from 1 and k). 1

%I #10 Jul 20 2024 14:34:50

%S 1,2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,

%T 89,97,101,103,107,109,113,121,127,131,137,139,143,149,151,157,163,

%U 167,169,173,179,181,187,191,193,197,199,209,211,221,223,227,229,233,239

%N Numbers k with no single-digit factors (apart from 1 and k).

%o (PARI) isok(n) = {d = divisors(n); for (i = 2, #d - 1,if (length(Str(d[i])) == 1, return (0));); return (1);} \\ _Michel Marcus_, Jul 27 2013

%Y Cf. A008364.

%K nonn,base

%O 1,2

%A _Henry Bottomley_, Mar 14 2000

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Last modified August 12 12:15 EDT 2024. Contains 375092 sequences. (Running on oeis4.)