A141438 Primes p such that p+4 is prime and (p+5)/6 is composite.

19, 43, 67, 79, 103, 127, 163, 193, 223, 229, 307, 379, 439, 457, 463, 487, 499, 643, 739, 769, 823, 853, 859, 877, 883, 907, 967, 1009, 1087, 1093, 1213, 1279, 1297, 1303, 1423, 1447, 1483, 1489, 1549, 1567, 1579, 1597, 1663, 1783, 1867, 1993, 1999, 2083, 2137, 2203, 2239, 2347, 2389, 2437, 2473, 2539, 2617, 2659, 2683, 2707, 2749, 2833, 2857

Offset

1,1

Links

Table of n, a(n) for n=1..63.

Maple

a:=[];
for n from 1 to 420 do
p:=ithprime(n); p1:=p+4; p2:=(p+5)/6;
if isprime(p1) and whattype(p2)=integer and not isprime(p2) then a:=[op(a), p]; fi;
od:
a; # N. J. A. Sloane, Mar 09 2024

Crossrefs

Cf. A002808, A000040.

Sequence in context: A238676 A087779 A106950 * A350051 A095103 A094843

Adjacent sequences: A141435 A141436 A141437 * A141439 A141440 A141441

Keyword

nonn

Author

Juri-Stepan Gerasimov, Aug 28 2008

Extensions

Entry corrected by the combined efforts of Bill McEachen, R. J. Mathar, Jon E. Schoenfield, Alois P. Heinz, and N. J. A. Sloane, Mar 09 2024

Status

approved