%I #9 Jun 04 2023 17:32:22
%S 0,1,21,27,45,55,57,63,65,69,77,87,91,115,121,125,141,145,175,185,195,
%T 201,203,215,219,235,237,279,289,291,295,299,305,315,319,335,339,343,
%U 381,385,435,437,441,477,497,507,533,539,543,549,561,567,581,591,629,639,649
%N Nonprimes of the form (p(n)-2*n)/5, where p(n)=n-th prime.
%H Harvey P. Dale, <a href="/A144415/b144415.txt">Table of n, a(n) for n = 1..2500</a>
%e a(1) = (p(1)-2*1)/5 = (2-2)/5 = 0.
%e a(2) = (p(9)-2*9)/5 = (23-18)/5 = 1.
%t Select[Table[(Prime[n]-2n)/5,{n,1000}],IntegerQ[#]&&!PrimeQ[#]&]//Union (* _Harvey P. Dale_, Jun 04 2023 *)
%K nonn,easy,less
%O 1,3
%A _Juri-Stepan Gerasimov_, Oct 07 2008
%E Corrected and extended by _Charles R Greathouse IV_, Mar 26 2010