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 A110675 Numbers n such that the string 2222n is the decimal expansion of a prime number. 1
 9, 47, 69, 89, 93, 123, 141, 147, 167, 177, 203, 219, 239, 243, 249, 251, 263, 273, 281, 287, 293, 309, 317, 321, 327, 333, 351, 377, 383, 387, 443, 477, 501, 503, 509, 527, 533, 537, 543, 567, 573, 579, 593, 599, 611, 617, 621, 629, 653, 659, 663, 683 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE 177 is in the sequence because 2222177 is prime. MATHEMATICA Select[Range[700], PrimeQ[FromDigits[Join[{2, 2, 2, 2}, IntegerDigits[ #]]]]&] (* Harvey P. Dale, Nov 14 2014 *) PROG (Magma) [ n: n in [1..700] | IsPrime(Seqint(Intseq(n) cat [2, 2, 2, 2])) ]; // Klaus Brockhaus, Feb 01 2011 CROSSREFS Sequence in context: A250776 A054140 A307955 * A265805 A274270 A100790 Adjacent sequences: A110672 A110673 A110674 * A110676 A110677 A110678 KEYWORD nonn,base AUTHOR Parthasarathy Nambi, Sep 14 2005 STATUS approved

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Last modified February 6 20:15 EST 2023. Contains 360111 sequences. (Running on oeis4.)