A238713 - OEIS

%I #11 Jan 19 2019 04:11:21

%S 11,41,71,101,131,191,223,311,431,461,613,641,821,853,881,1031,1061,

%T 1091,1301,1423,1451,1481,1601,1663,1693,1783,1871,1993,2081,2381,

%U 2683,2711,3163,3251,3461,3671,3761,3911,4001,4091,4153,4211,4513,4721,4783,4931

%N Least member of decadal prime triples: First prime beyond 10*A008470(n).

%H Charles R Greathouse IV, <a href="/A238713/b238713.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = nextprime(10*A008470(n)).

%o (PARI) for(d=1,999,primepi(10*(d+1))-primepi(10*d) >2|next; print1(nextprime(d*10+1)","))

%o (PARI) is(n)=my(t=n%10); if(t==1, isprime(n) && if(isprime(n+2), isprime(n+6) || isprime(n+8), isprime(n+6) && isprime(n+8)), t==3 && isprime(n) && !isprime(n-2) && isprime(n+4) && isprime(n+6)) \\ _Charles R Greathouse IV_, Mar 04 2014

%Y Cf. A008470, A008471, A238715.

%K nonn

%O 1,1

%A _M. F. Hasler_, Mar 03 2014