A143390 Numbers in which every suffix (in base 10) is 1 or a prime.

1, 2, 3, 5, 7, 11, 13, 17, 23, 31, 37, 41, 43, 47, 53, 61, 67, 71, 73, 83, 97, 101, 103, 107, 113, 131, 137, 167, 173, 197, 211, 223, 241, 271, 283, 307, 311, 313, 317, 331, 337, 347, 353, 367, 373, 383, 397, 401, 431, 443, 461, 467, 503, 523, 541, 547, 571, 601

Offset: 1

Author

Reinhard Zumkeller, Aug 13 2008

Keywords

• nonn
• base

Comments

Subsequence of A042986 apart from first term; a(n+1)=A042986(n) for n<25.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A012883, A012884.

Programs

Mathematica

prQ[n_] := n == 1 || PrimeQ[n];
okQ[n_] := Module[{dd = IntegerDigits[n]}, AllTrue[Range[Length[dd]-1], prQ@ FromDigits@ Drop[dd, #]&]];
{1}~Join~Select[ Prime@Range[1000], okQ] (* Jean-François Alcover, Nov 20 2019 *)

PARI

is(n)=my(d=digits(n,10)); for(i=1,#d-1, if(!isprime(fromdigits(d[i..#d],10)), return(0))); isprime(d[#d]) || d[#d]==1 \\ Charles R Greathouse IV, Nov 26 2016