A238730 - OEIS

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

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OFFSET

1,1

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

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