A102414 Smallest semiprime greater than n-th prime.

4, 4, 6, 9, 14, 14, 21, 21, 25, 33, 33, 38, 46, 46, 49, 55, 62, 62, 69, 74, 74, 82, 85, 91, 106, 106, 106, 111, 111, 115, 129, 133, 141, 141, 155, 155, 158, 166, 169, 177, 183, 183, 194, 194, 201, 201, 213, 226, 235, 235, 235, 247, 247, 253, 259, 265, 274, 274

Offset: 1

Author

Reinhard Zumkeller, Jan 08 2005

Keywords

• nonn

Comments

A102415(n) < A000040(n) < a(n).

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• Eric Weisstein's World of Mathematics, Semiprime

Crossrefs

Cf. A001358.

Programs

Mathematica

ssp[n_]:=Module[{k=n+1},While[PrimeOmega[k]!=2,k++];k]; ssp/@Prime[Range[ 60]] (* Harvey P. Dale, Aug 18 2012 *)

PARI

a(n) = {sp = prime(n)+1; while(bigomega(sp) != 2, sp++); sp;} \\ Michel Marcus, Mar 04 2017