A230098 a(n) = n*prime(prime(n)) - prime(n)^2.

-1, 1, 8, 19, 34, 77, 124, 175, 218, 249, 436, 515, 646, 825, 956, 1047, 1228, 1373, 1800, 2019, 2378, 2581, 3024, 3143, 3316, 4021, 4592, 4987, 5490, 5741, 5850, 6487, 6740, 7777, 7864, 8771, 9354, 10177, 10760, 11311, 11542, 12893, 13098, 14275, 15236, 16381, 16438, 17903, 18688, 19909, 20732, 20827, 22638

Offset: 1

Author

N. J. A. Sloane, Oct 12 2013

Keywords

• sign

Programs

Magma

[n*NthPrime(NthPrime(n)) - NthPrime(n)^2: n in [1..60]]; // Vincenzo Librandi, Oct 13 2013

Mathematica

Table[n Prime[Prime[n]]-Prime[n]^2,{n,60}] (* Harvey P. Dale, Mar 16 2017 *)

PARI

a(n) = n*prime(prime(n)) - prime(n)^2; \\ Joerg Arndt, Oct 21 2013

Formula

a(n) = A080697(n) - A001248(n). - Omar E. Pol, Oct 21 2013