A238730 The largest prime in each decade (10k,10k+10) containing at least three primes.

7, 19, 47, 79, 109, 139, 199, 229, 317, 439, 467, 619, 647, 829, 859, 887, 1039, 1069, 1097, 1307, 1429, 1459, 1489, 1609, 1669, 1699, 1789, 1879, 1999, 2089, 2389, 2689, 2719, 3169, 3259, 3469, 3677, 3769, 3919, 4007, 4099, 4159, 4219, 4519, 4729, 4789, 4937, 5237, 5419, 5449, 5479, 5507, 5659, 5749, 5869, 6709, 6829

Offset: 1

Author

M. F. Hasler, Mar 03 2014

Keywords

• nonn

Comments

The initial term 7 does not correspond to a "decadal prime triple" according to the strict definition of A008470.

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A008470, A008471, A238713, A238715.

Programs

Maple

f:= proc(k) local P;
   P:= select(isprime, [10*k+1,10*k+3,10*k+7,10*k+9]);
   if nops(P) >= 3 then max(P) fi
end proc:f(0):= 7:map(f, [$0..1000]); # Robert Israel, Jun 08 2020

PARI

p=0; for(d=1,999,2+p < (p=primepi(10*d)) && print1(precprime(d*10)","))