A062353 Primes of the form bbbbba... where a and b are digits.

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 113, 223, 227, 229, 331, 337, 443, 449, 557, 661, 773, 881, 883, 887, 991, 997, 1117, 2221, 3331, 4441, 4447, 5557, 6661, 8887, 11113, 11117, 11119, 22229

Offset

1,1

Comments

Number of terms of n digits: 4, 21, 16, 8, 9, 8, 2, 8, 7, 3, 4, 5, 2, 2, 4, 0, 3, 4, 2, 3, 2, 2, 4, 1, 0, ..., . - Robert G. Wilson v, May 29 2011

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..260

Example

4441 is a member where a=1 and b = 4.

Mathematica

f[n_] := Select[ Union@ Flatten@ Table[ FromDigits@ Join[ Table[b, {n - 1}], {a}], {b, 9}, {a, {1, 3, 7, 9}}], PrimeQ]; f[1] = {2, 3, 5, 7}; Array[f, 5] // Flatten (* Robert G. Wilson v, May 29 2011 *)

Prog

(PARI) print1("2, 3, 5, 7"); for(n=2, 20, forstep(k=10^n\9-1, 10^n-9, 10^n\9-1, for(m=k+1, k+9, if(isprime(m), print1(", "m))))) \\ Charles R Greathouse IV, May 29 2011

Crossrefs

Cf. A061022.

Sequence in context: A038618 A030475 A069676 * A077390 A069677 A069678

Adjacent sequences: A062350 A062351 A062352 * A062354 A062355 A062356

Keyword

nonn,base,easy

Author

Amarnath Murthy, Jun 23 2001

Extensions

More terms from Jason Earls, Jun 26 2001

Corrected and extended by Dean Hickerson, Jul 10 2001

Status

approved