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 A275247 a(n) = number of decimal digits of A007505(n). 0
 1, 1, 2, 2, 2, 3, 3, 4, 6, 11, 12, 14, 18, 20, 24, 29, 32, 44, 63, 66, 93, 99, 119, 139, 142, 250, 384, 987, 1267, 1546, 2276, 3817, 4486, 5457, 5666, 7734, 7966, 12532, 15470, 21610, 24183, 25795, 26543, 29220, 37217, 46941, 49667, 70671, 124880, 176102, 211335, 219060, 298833, 361552, 370947, 696203, 944108, 1274988, 1833429, 3457035, 3531640, 3580969 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS FORMULA a(n) = A055642(A007505(n)). - Michel Marcus, Jul 23 2016 CROSSREFS Cf. A055642, A007505 (primes of form 3*2^n-1), A002235 (numbers n such that 3*2^n-1 is prime). Sequence in context: A029054 A008997 A005851 * A293440 A237121 A139821 Adjacent sequences:  A275244 A275245 A275246 * A275248 A275249 A275250 KEYWORD base,nonn AUTHOR Zak Seidov, Jul 21 2016 STATUS approved

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Last modified April 20 17:54 EDT 2019. Contains 322310 sequences. (Running on oeis4.)