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 A117819 Final digit d of n is in the sequence iff d is prime or n is prime. 1

%I

%S 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,

%T 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,

%U 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

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

%e Calculations:

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

%e d: - 2 3 - 5 - 7 - - -- -1 -2 -3 -- -5 -- -7 -- -9 -- ...

%t Table[If[PrimeQ[n]||PrimeQ[Mod[n,10]],Mod[n,10],Nothing],{n,300}] (* _Harvey P. Dale_, Oct 03 2016 *)

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

%Y Cf. A118385.

%K base,easy,nonn

%O 1,1

%A _Giovanni Teofilatto_, Apr 30 2006

%E Edited, corrected and extended by _Klaus Brockhaus_, May 02 2006

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Last modified June 18 14:52 EDT 2019. Contains 324213 sequences. (Running on oeis4.)