cp's OEIS Frontend

A268068 First occurrence of n in the decimal expansion of Mersenne prime 2^74207281 - 1.

%I A268068 #36 Apr 08 2024 09:14:51
%S A268068 2,8,18,1,7,20,6,5,9,22,167,240,196,156,51,143,31,241,8,74,18,73,138,
%T A268068 71,154,217,96,119,160,21,1,166,72,63,64,28,87,4,172,57,210,7,81,56,
%U A268068 103,65,12,68,52,374,35,239,20,90,67,66,38,178,42,29,13,15,174,44,6
%N A268068 First occurrence of n in the decimal expansion of Mersenne prime 2^74207281 - 1.
%C A268068 The largest known prime as of Jan 07 2016 is 2^74207281 - 1. The number itself contains 22,338,618 digits; all integers with fewer than 7 digits are contained within M74207281. The first number not contained in M74207281 is 1000003, so this sequence stops at a(1000002) = 1505496.
%H A268068 Michael P. Tilley, <a href="/A268068/b268068.txt">Table of n, a(n) for n = 0..9999</a>
%H A268068 Brady Haran and Matt Parker, <a href="https://www.youtube.com/watch?v=jNXAMBvYe-Y">More details about the World's Biggest Prime</a> (2016).
%H A268068 Michael P. Tilley, <a href="http://miketilley.com/downloads/b268068-1M.txt">A larger file of the sequence for n= 0 - 1000002</a>
%e A268068 The first few digits of M74207281 are 30037641808460618205298609835916605...
%e A268068 Starting with three as the first digit count the position of n from the beginning
%e A268068   0 is the second digit,
%e A268068   1 is the eighth digit,
%e A268068   2 18,
%e A268068   3 1,
%e A268068   4 7,
%e A268068   etc.
%t A268068 With[{m = IntegerDigits[2^74207281 - 1]}, Array[SequencePosition[m, IntegerDigits[#], 1][[1, 1]] &, 100, 0]] (* _Paolo Xausa_, Apr 07 2024 *)
%Y A268068 Cf. A000043, A267875.
%K A268068 nonn,base,fini
%O A268068 0,1
%A A268068 _Michael P. Tilley_, Jan 25 2016