OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
5503 is a member because
5503 = (5431 + 5437 + 5441 + 5443 + 5449 + 5471 + 5477 + 5479 + 5483 + 5501 + 5503 + 5507 + 5519 + 5521 + 5527 + 5531 + 5557 + 5563 + 5569 + 5573 + 5581)/21 = 115563/21.
MATHEMATICA
Transpose[ Select[ Partition[ Prime[ Range[10000]], 21, 1], #[[11]] == (#[[1]] + #[[2]] + #[[3]] + #[[4]] + #[[5]] + #[[6]] + #[[7]] + #[[8]] + #[[9]] + #[[10]] + #[[12]] + #[[13]] + #[[14]] + #[[15]] + #[[16]] + #[[17]] + #[[18]] + #[[19]] + #[[20]] + #[[21]])/20 &]][[11]]
Transpose[Select[Partition[Prime[Range[9000]], 21, 1], Total[#]/21 == #[[11]]&]][[11]] (* Harvey P. Dale, Mar 09 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jun 26 2004
STATUS
approved