A117819 Final digit d of n is in the sequence iff d is prime or n is prime.

2, 3, 5, 7, 1, 2, 3, 5, 7, 9, 2, 3, 5, 7, 9, 1, 2, 3, 5, 7, 1, 2, 3, 5, 7, 2, 3, 5, 7, 9, 1, 2, 3, 5, 7, 1, 2, 3, 5, 7, 9, 2, 3, 5, 7, 9, 2, 3, 5, 7, 1, 2, 3, 5, 7, 9, 2, 3, 5, 7, 2, 3, 5, 7, 1, 2, 3, 5, 7, 9, 2, 3, 5, 7, 9, 1, 2, 3, 5, 7, 2, 3, 5, 7, 2, 3, 5, 7, 9, 1, 2, 3, 5, 7, 1, 2, 3, 5, 7, 9, 2, 3, 5, 7, 1

Offset

1,1

Links

Table of n, a(n) for n=1..105.

Example

Calculations:
n: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 ...
d: - 2 3 - 5 - 7 - - -- -1 -2 -3 -- -5 -- -7 -- -9 -- ...

Mathematica

Table[If[PrimeQ[n]||PrimeQ[Mod[n, 10]], Mod[n, 10], Nothing], {n, 300}] (* Harvey P. Dale, Oct 03 2016 *)

Prog

(PARI) for(n=1, 211, if(isprime(d=n%10)||isprime(n), print1(d, ", ")))

Crossrefs

Cf. A118385.

Sequence in context: A228355 A065859 A258062 * A074461 A285095 A073342

Adjacent sequences: A117816 A117817 A117818 * A117820 A117821 A117822

Keyword

base,easy,nonn

Author

Giovanni Teofilatto, Apr 30 2006

Extensions

Edited, corrected and extended by Klaus Brockhaus, May 02 2006

Status

approved