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 A147554 Primes p such that p^2 divides p.p.p where dot "." means concatenation. 2
 3, 13, 37, 9901, 333667, 99990001, 999999000001, 9999999900000001, 13168164561429877, 130654897808007778425046117 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes p dividing 10^(2*d)+10^d+1 where d=ceiling(log(p)/log(10)) is the number of decimal digits in p. - Max Alekseyev a(11) > 10^156. - Max Alekseyev, Feb 08 2021 There is no prime p such that p^2 divides p.p. All primes of the forms 10^(2m) - 10^m + 1 or (1/3)*(10^(2m) + 10^m + 1) are in the sequence. Primes in A243162. - Hans Havermann, May 31 2014 LINKS CROSSREFS Cf. A147553, A243162. Sequence in context: A120479 A146227 A019007 * A076800 A277411 A054975 Adjacent sequences: A147551 A147552 A147553 * A147555 A147556 A147557 KEYWORD nonn,base,more AUTHOR Farideh Firoozbakht, Dec 26 2008 STATUS approved

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Last modified December 3 20:26 EST 2022. Contains 358543 sequences. (Running on oeis4.)