A075342 a(1) = 1, a(n+1) is the smallest number such that there are n primes between a(n) and a(n+1) exclusive.

1, 3, 8, 18, 32, 54, 80, 110, 158, 200, 264, 332, 402, 480, 578, 662, 774, 888, 1022, 1154, 1298, 1460, 1610, 1788, 1994, 2162, 2378, 2610, 2798, 3042, 3314, 3548, 3804, 4080, 4364, 4664, 4988, 5310, 5648, 5954, 6312, 6690, 7028, 7482, 7842, 8264, 8690

Offset

1,2

Comments

3 is the only prime member, a(3) onwards a(n)-1 is prime.

Links

Table of n, a(n) for n=1..47.

Mathematica

Join[{1, 3}, Rest[(Prime[#]+1)&/@Table[(n(n+1))/2+1, {n, 50}]]] (* Harvey P. Dale, Jul 25 2011 *)

Prog

(PARI) a(n)=if(n<3, [1, 3][n], prime(n*(n-1)/2+1)+1) \\ Charles R Greathouse IV, Jul 24 2011

Crossrefs

Cf. A075343.

Sequence in context: A247022 A119881 A184636 * A083726 A319006 A212589

Adjacent sequences: A075339 A075340 A075341 * A075343 A075344 A075345

Keyword

nonn

Author

Amarnath Murthy, Sep 18 2002

Extensions

More terms from Sascha Kurz, Jan 30 2003

Status

approved