Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #24 May 10 2019 21:45:55
%S 0,1,2,4,8,9,10,11,14,16,17,22,23,24,25,28,30,34,35,36,39,41,43,46,48,
%T 50,53,55,56,60,63,64,65,69,74,77,78,79,80,81,83,85,86,91,93,98,99,
%U 101,102,107,108,109,111,112,115,116
%N Numbers k such that 90*k + 19 is prime.
%C A142322 is a digital root 1 and last digit 9 preserving sequence.
%H Ivan Neretin, <a href="/A196000/b196000.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = (A142322(n) - 19)/90.
%p A142322 := proc(n)
%p option remember;
%p if n = 1 then
%p 19 ;
%p else
%p a := nextprime(procname(n-1)) ;
%p while (a mod 45) <> 19 do
%p a := nextprime(a) ;
%p end do;
%p return a;
%p end if;
%p end proc:
%p A196000 := proc(n)
%p (A142322(n)-19)/90 ;
%p end proc:
%p seq(A196000(n),n=1..80) ; # _R. J. Mathar_, Oct 31 2011
%t Select[Range[0, 120], PrimeQ[90 # + 19] &] (* _Ivan Neretin_, Apr 27 2017 *)
%o (PARI) is(n)=isprime(90*n+19) \\ _Charles R Greathouse IV_, Apr 25 2016
%Y Cf. A195953, A181732, A198382.
%K nonn,easy
%O 1,3
%A _J. W. Helkenberg_, Oct 27 2011