OFFSET
1,1
LINKS
Zak Seidov, Table of n, a(n) for n = 1..10000
EXAMPLE
983 is a member because 983 = (919 + 929 + 937 + 941 + 947 + 953 + 967 + 971 + 977 + 983 + 991 + 997 + 1009 + 1013 + 1019 + 1021 + 1031 + 1033 + 1039)/19 = 18677/19.
MATHEMATICA
Transpose[ Select[ Partition[ Prime[ Range[7500]], 19, 1], #[[10]] == (#[[1]] + #[[2]] + #[[3]] + #[[4]] + #[[5]] + #[[6]] + #[[7]] + #[[8]] + #[[9]] + #[[11]] + #[[12]] + #[[13]] + #[[14]] + #[[15]] + #[[16]] + #[[17]] + #[[18]] + #[[19]])/18 &]][[10]]
#[[10]] & /@ Select[Partition[Prime[Range[7500]], 19, 1], #[[10]] == Mean[#] &] (* Zak Seidov, Mar 01 2017 *)
PROG
(GAP) P:=Filtered([1..80000], IsPrime);;
a:=List(Filtered(List([0..6000], k->List([10..28], j->P[j-9+k])), i->
Sum(i)/19=i[10]), m->m[10]); # Muniru A Asiru, Feb 14 2018
(PARI) isok(p) = {if (isprime(p), k = primepi(p); if (k > 9, sum(i=k-9, k+9, prime(i)) == 19*p; ); ); } \\ Michel Marcus, Mar 07 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jun 26 2004
STATUS
approved