A230098 - OEIS

%I #15 Sep 08 2022 08:46:06

%S -1,1,8,19,34,77,124,175,218,249,436,515,646,825,956,1047,1228,1373,

%T 1800,2019,2378,2581,3024,3143,3316,4021,4592,4987,5490,5741,5850,

%U 6487,6740,7777,7864,8771,9354,10177,10760,11311,11542,12893,13098,14275,15236,16381,16438,17903,18688,19909,20732,20827,22638

%N a(n) = n*prime(prime(n)) - prime(n)^2.

%F a(n) = A080697(n) - A001248(n). - _Omar E. Pol_, Oct 21 2013

%t Table[n Prime[Prime[n]]-Prime[n]^2,{n,60}] (* _Harvey P. Dale_, Mar 16 2017 *)

%o (Magma) [n*NthPrime(NthPrime(n)) - NthPrime(n)^2: n in [1..60]]; // _Vincenzo Librandi_, Oct 13 2013

%o (PARI) a(n) = n*prime(prime(n)) - prime(n)^2; \\ _Joerg Arndt_, Oct 21 2013

%K sign

%O 1,3

%A _N. J. A. Sloane_, Oct 12 2013