A194267 Smallest sum of three distinct primes of the form n*k+1.
10, 15, 39, 35, 83, 39, 143, 131, 129, 83, 179, 111, 263, 143, 243, 227, 479, 129, 839, 203, 381, 179, 463, 363, 503, 263, 543, 339, 641, 243, 1367, 547, 597, 479, 563, 219, 965, 839, 549, 563, 1643, 381, 1551, 839, 993, 463, 1883, 531, 1571, 503, 819, 523
Offset: 1
Keywords
Examples
a(1) = 2+3+5 = 10. a(2) = 3+5+7 = 15. a(3) = 7+13+19 = 39. a(4) = 5+13+17 = 35. a(5) = 11+31+41 = 83. a(6) = 7+13+19 = 39.
Links
- Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
Table[ps = Select[Table[n*k + 1, {k, 100}], PrimeQ, 3]; If[Length[ps] == 3, Total[ps], 0], {n, 100}] (* T. D. Noe, Oct 21 2011 *)