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A342480
a(n) is the denominator of the asymptotic density of numbers whose second smallest prime divisor (A119288) is prime(n).
3
1, 6, 10, 15, 1155, 1365, 12155, 1616615, 37182145, 11849255, 33426748355, 247357937827, 10141675450907, 25652473199353, 2928046583754721, 155186468939000213, 223317113839049087, 558516101711461766587, 796182527971658263007, 241532826894674874877669, 430046252763689411367557
OFFSET
1,2
COMMENTS
See A342479 for details.
LINKS
MATHEMATICA
f[n_] := Module[{p = Prime[n], q}, q = Select[Range[p - 1], PrimeQ]; Plus @@ (1/(q - 1))*Times @@ ((q - 1)/q)/p]; Denominator @ Array[f, 30]
CROSSREFS
Cf. A038110, A038111, A119288, A342479 (numerators).
Sequence in context: A319035 A117309 A228300 * A299996 A315289 A108936
KEYWORD
nonn,easy,frac
AUTHOR
Amiram Eldar, Mar 13 2021
STATUS
approved