A136241 Numbers n among A006093 such that n^2 + n - 1 is prime.
2, 4, 6, 10, 16, 28, 30, 46, 60, 66, 70, 96, 100, 126, 130, 138, 148, 180, 196, 240, 268, 306, 330, 358, 378, 396, 408, 418, 420, 448, 456, 478, 486, 490, 598, 606, 616, 618, 640, 646, 676, 708, 750, 786, 838, 856, 906, 946, 966, 976, 996, 1050, 1060, 1090
Offset: 1
Keywords
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
Select[Prime[Range[200]]-1,PrimeQ[#^2+#-1]&] (* Harvey P. Dale, Jan 20 2019 *)
Formula
a(n) = A091567(n) - 1.