A106100 Primes with maximal digit = 2.

2, 211, 1021, 1201, 2011, 2111, 2221, 10211, 12011, 12101, 12211, 20011, 20021, 20101, 20201, 21001, 21011, 21101, 21121, 21211, 21221, 22111, 101021, 101221, 102001, 102101, 102121, 110221, 111121, 111211, 112111, 112121, 120011, 120121

Offset: 1

Author

Zak Seidov, May 07 2005

Keywords

• nonn
• base

Comments

Subsequence of A036953. Prime numbers p such that A209928(p) = 2. Complement of A221698 with respect to A221697. [Jaroslav Krizek, Jan 22 2013]

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A106093, A106094, A106095, A106096, A106097, A106098, A106099.

Programs

Maple

N:= 6: # to get all terms of up to N digits
M2:= {1};M1:= {1}:
for d from 1 to N-1 do
  M2:= map(t -> (t, t+10^d, t+2*10^d), M2);
  M1:= map(t -> (t, t+10^d), M1);
od:
sort(convert({2} union select(isprime,M2 minus M1),list)); # Robert Israel, Jun 19 2016

Mathematica

Select[Prime[Range[10000]], Max[IntegerDigits[ # ]]==2&]

PARI

isok(p) = isprime(p) && (vecmax(digits(p)) == 2); \\ Michel Marcus, Jan 02 2019

Extensions

More terms from Rick L. Shepherd, May 22 2005