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A141138
a(n) = prime(A028815(n) - 1) - 1.
6
1, 2, 4, 10, 16, 30, 40, 58, 66, 82, 108, 126, 156, 178, 190, 210, 240, 276, 282, 330, 352, 366, 400, 430, 460, 508, 546, 562, 586, 598, 616, 708, 738, 772, 796, 858, 876, 918, 966, 990, 1030, 1062, 1086, 1152, 1170, 1200, 1216, 1296, 1408, 1432, 1446, 1470
OFFSET
0,2
LINKS
FORMULA
a(n) = A000040(A000040(n)) - 1, with a(0) = 1. - G. C. Greubel, Aug 05 2024
MATHEMATICA
A141138[n_]:= If[n==0, 1, Prime[Prime[n]] -1];
Table[A141138[n], {n, 0, 70}] (* G. C. Greubel, Aug 05 2024 *)
PROG
(Magma)
A141138:= func< n | n eq 0 select 1 else NthPrime(NthPrime(n)) -1 >;
[A141138(n): n in [0..50]]; // G. C. Greubel, Aug 05 2024
(SageMath)
def A141138(n): return 1 if n==0 else nth_prime(nth_prime(n))-1
[A141138(n) for n in range(71)] # G. C. Greubel, Aug 05 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(14), a(28) corrected by D. S. McNeil, Mar 21 2009
Offset changed by G. C. Greubel, Aug 05 2024
STATUS
approved