A248934 - OEIS

%I #15 Sep 08 2022 08:46:10

%S 2,5,9,1,1,7,0,8,6,0,1,3,2,0,2,6,2,7,7,7,6,2,4,6,7,6,7,9,2,2,4,4,1,5,

%T 3,0,9,4,1,8,1,8,8,8,7,5,5,3,1,2,5,4,2,7,3,0,3,9,7,4,9,2,3,1,6,1,8,7,

%U 4,0,1,9,2,6,6,5,8,6,3,6,2,0,8,6,2,0,1,2,0,9,5,1,6,8,0,0,4,8,3,4,0,6,5,5,0

%N Decimal expansion of 2^3217 - 1, the 18th Mersenne prime A000668(18).

%C The prime was found on September 8, 1957, by Hans Riesel, using BESK.

%H Arkadiusz Wesolowski, <a href="/A248934/b248934.txt">Table of n, a(n) for n = 969..1937</a>

%H Hans Riesel, <a href="http://www.ams.org/journals/mcom/1958-12-061/S0025-5718-1958-0099752-6/S0025-5718-1958-0099752-6.pdf">A New Mersenne Prime</a>, Mathematics of Computation, vol. 12 (1958), p. 60.

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Mersenne_prime">Mersenne prime</a>

%F Equals 2^A000043(18) - 1.

%e 25911708601320262777624676792244153094181888755312542730397492316187401...

%t RealDigits[2^3217 - 1, 10, 100][[1]] (* _G. C. Greubel_, Oct 03 2017 *)

%o (Magma) Reverse(Intseq(2^3217-1));

%o (PARI) eval(Vec(Str(2^3217-1)))

%Y Cf. A169684 = A000668(11), A169681 = A000668(12), A169685 = A000668(13), A204063 = A000668(14), A248931 = A000668(15), A248932 = A000668(16), A248933 = A000668(17), A248935 = A000668(19), A248936 = A000668(20).

%K nonn,cons,easy,fini,full

%O 969,1

%A _Arkadiusz Wesolowski_, Oct 17 2014