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

2, 8, 18, 1, 7, 20, 6, 5, 9, 22, 167, 240, 196, 156, 51, 143, 31, 241, 8, 74, 18, 73, 138, 71, 154, 217, 96, 119, 160, 21, 1, 166, 72, 63, 64, 28, 87, 4, 172, 57, 210, 7, 81, 56, 103, 65, 12, 68, 52, 374, 35, 239, 20, 90, 67, 66, 38, 178, 42, 29, 13, 15, 174, 44, 6

Offset: 0

Author

Michael P. Tilley, Jan 25 2016

Keywords

• nonn
• base
• fini

Comments

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.

Examples

			The first few digits of M74207281 are 30037641808460618205298609835916605...
Starting with three as the first digit count the position of n from the beginning
  0 is the second digit,
  1 is the eighth digit,
  2 18,
  3 1,
  4 7,
  etc.
		

Links

• Michael P. Tilley, Table of n, a(n) for n = 0..9999
• Brady Haran and Matt Parker, More details about the World's Biggest Prime (2016).
• Michael P. Tilley, A larger file of the sequence for n= 0 - 1000002

Crossrefs

Cf. A000043, A267875.

Programs

Mathematica

With[{m = IntegerDigits[2^74207281 - 1]}, Array[SequencePosition[m, IntegerDigits[#], 1][[1, 1]] &, 100, 0]] (* Paolo Xausa, Apr 07 2024 *)