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A062353
Primes of the form bbbbba... where a and b are digits.
3
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
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