OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
107 is the lesser of twin prime pair (107,109) the prime index of 109 (the greater) is 29.
MATHEMATICA
seq = {}; p = prv = 2; k = 1; Do[p = NextPrime[p]; k++; If[p == prv + 2 && PrimeQ[k], AppendTo[seq, prv]]; prv = p, {10^3}]; seq
Select[Partition[Prime[Range[2000]], 2, 1], #[[2]]-#[[1]]==2&&PrimeQ[PrimePi[ #[[2]]]]&] [[All, 1]] (* Harvey P. Dale, Nov 30 2022 *)
PROG
(PARI) lista(n) = {forprime(x=2, n, y=prime(x)- 2; if(isprime(y), print1(y", ")))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Cino Hilliard, May 31 2004
EXTENSIONS
Offset corrected by Amiram Eldar, Dec 27 2019
STATUS
approved