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 A290432 Numbers k such that 9*10^k + 59 is prime. 0
 1, 3, 4, 6, 7, 12, 17, 28, 46, 75, 105, 309, 351, 460, 774, 785, 2206, 5739, 12427, 14501, 17950, 68331 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS For k > 1, numbers such that the digit 9 followed by k-2 occurrences of the digit 0 followed by the digits 59 is prime (see Example section). a(23) > 10^5. LINKS Makoto Kamada, Factorization of near-repdigit-related numbers. Makoto Kamada, Search for 90w59 EXAMPLE 3 is in this sequence because 9*10^3 + 59 = 9059 is prime. Initial terms and primes associated: a(1) = 1, 149; a(2) = 3, 9059; a(3) = 4, 90059; a(4) = 6, 9000059; a(5) = 7, 90000059; etc. MATHEMATICA Select[Range[0, 100000], PrimeQ[9*10^# + 59] &] CROSSREFS Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269. Sequence in context: A211384 A281828 A002982 * A276783 A288731 A093707 Adjacent sequences:  A290429 A290430 A290431 * A290433 A290434 A290435 KEYWORD nonn,more,hard AUTHOR Robert Price, Oct 06 2017 STATUS approved

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