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A196007
Numbers n such that 90n + 83 is prime.
19
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
1,3
LINKS
FORMULA
a(n) = (A142332(n)-83)/90.
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 *)
PROG
(PARI) is(n)=isprime(90*n+83) \\ Charles R Greathouse IV, Jul 12 2016
CROSSREFS
Cf. A196000, A198382, A181732, A195993. These are digital root and last digit preserving sequences.
Sequence in context: A250051 A076079 A229593 * A134170 A276560 A339577
KEYWORD
nonn,easy
AUTHOR
J. W. Helkenberg, Oct 27 2011
STATUS
approved