OFFSET
1,2
COMMENTS
At least one of a(n), a(n)+2, a(n)+4 and a(n)+6 must be a power of 3. See comments in A264734.
EXAMPLE
5 is a term because 5, 7, 11 are prime numbers and 9 = 3^2.
23 is a term because 23 and 29 are prime numbers and 25 = 5^2, 27 = 3^3.
25 is a term because 25 = 5^2, 27 = 3^3, 29 and 31 are prime numbers.
MATHEMATICA
Select[Range[0, 10^5], AllTrue[Range[0, 6, 2] + #, Or[# == 1, PrimePowerQ@ #] &] &] (* Michael De Vlieger, Mar 04 2016, Version 10 *)
PROG
(PARI) lista(nn) = for(n=1, nn, if(n==1 || (isprimepower(n) && isprimepower(n+2) && isprimepower(n+4) && isprimepower(n+6)), print1(n, ", ")));
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Altug Alkan, Mar 04 2016
STATUS
approved