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 A093675 Primes of the form 7*10^n + 3*R_n, where R_n is the repunit (A002275) of length n. 2
 7, 73, 733, 7333, 733333, 733333333333333333333333333333333333333333333333333333, 733333333333333333333333333333333333333333333333333333333 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The next term (a(8)) has 344 digits. - Harvey P. Dale, Nov 11 2014 LINKS Makoto Kamada, Prime numbers of the form 733...33. MATHEMATICA Select[Table[FromDigits[PadRight[{7}, n, 3]], {n, 500}], PrimeQ] (* Harvey P. Dale, Nov 11 2014 *) PROG (MAGMA) [a: n in [0..200] | IsPrime(a) where a is (22*10^n-1) div 3 ]; // Vincenzo Librandi, May 08 2019 CROSSREFS Cf. A002275, A056720 (corresponding n). Sequence in context: A009142 A155614 A113033 * A121127 A071060 A092444 Adjacent sequences:  A093672 A093673 A093674 * A093676 A093677 A093678 KEYWORD nonn AUTHOR Rick L. Shepherd, Apr 08 2004 STATUS approved

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Last modified December 9 19:51 EST 2019. Contains 329879 sequences. (Running on oeis4.)