A196007 Numbers n such that 90n + 83 is prime.

0, 1, 2, 3, 4, 10, 12, 15, 16, 17, 21, 22, 23, 24, 25, 26, 29, 32, 36, 37, 39, 42, 45, 49, 50, 51, 54, 58, 59, 60, 61, 64, 67, 68, 71, 72, 73, 75, 77, 78, 79, 80, 84, 86, 89, 91, 92, 94, 101, 105, 106, 108, 112, 113, 114, 115, 117, 120

Offset: 1

Author

J. W. Helkenberg, Oct 27 2011

Keywords

• nonn
• easy

Links

• Ivan Neretin, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A196000, A198382, A181732, A195993. These are digital root and last digit preserving sequences.

Programs

Maple

A142332 := proc(n)
        option remember;
        if n = 1 then
                83 ;
        else
                a := nextprime(procname(n-1)) ;
                while (a mod 45) <> 38 do
                        a := nextprime(a) ;
                end do;
                return a;
        end if;
end proc:
A196007 := proc(n)
        (A142332(n)-83)/90 ;
end proc:
seq(A196007(n),n=1..80) ; # R. J. Mathar, Oct 31 2011

Mathematica

Select[Range[0, 120], PrimeQ[90 # + 83] &] (* Ivan Neretin, May 02 2017 *)

PARI

is(n)=isprime(90*n+83) \\ Charles R Greathouse IV, Jul 12 2016

Formula

a(n) = (A142332(n)-83)/90.