A264735 a(n) = prime(2^(n-1)*(2*n-1)), n >= 1.
2, 13, 71, 263, 827, 2377, 6379, 16603, 41611, 101573, 243473, 573637, 1333613, 3065983, 6975971, 15746347, 35277211, 78510373, 173717329, 382404863, 837870343, 1828047503, 3973066781, 8604768101, 18576139177, 39983413319
Offset: 1
Keywords
Programs
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Magma
[NthPrime(2^(n-1)*(2*n-1)): n in [1..20]]; // Vincenzo Librandi, Nov 23 2015
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Mathematica
Table[Prime[2^(n - 1)*(2*n - 1)], {n, 26}] -
PARI
a(n)=if(n<1,print1("Error n < 1"),prime(2^(n-1)*(2*n-1))) \\ Anders Hellström, Nov 23 2015 -
Perl
use ntheory ":all"; say "$ ",nth_prime(2**($-1) * (2*$-1)) for 1..50; # _Dana Jacobsen, Apr 28 2017
Formula
a(n) = A000040(2^(n-1)*(2*n-1)).