OFFSET
1,1
EXAMPLE
7 < 4*2 < 11 < 4*3 < 13 < 17 < 19 < 5*3 < 23, so (a(1), a(2), a(3)) = (7,11,19).
MATHEMATICA
Table[Prime[PrimePi[4*Prime[n]]], {n, 1, 200}]
PROG
(PARI) a(n) = precprime(4*prime(n)); \\ Michel Marcus, Feb 10 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Feb 09 2024
STATUS
approved