A050208 Starting positions of strings of 2 1's in the decimal expansion of Pi.

94, 153, 154, 174, 362, 395, 427, 437, 445, 494, 709, 758, 846, 921, 983, 984, 1129, 1185, 1349, 1503, 1534, 1656, 1849, 1896, 2458, 2497, 2724, 2740, 2779, 2904, 3253, 3398, 3493, 3503, 3504, 3534, 3735, 3822, 3844, 3847, 3963, 3992, 3993

Offset: 1

Author

Eric W. Weisstein

Keywords

• nonn
• base

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Pi Digits
• Index entries for sequences related to the number Pi

Crossrefs

Cf. A037008, A037000, A037001, A037002, A037003, A037004, A037005, A036974, A037006, A037007, A014777, A134212, A134213, A134214, A134215, A134216, A134217, A134218, A134218, A134219.

Programs

Mathematica

a=RealDigits[Pi,10,8! ];lst={};Do[b=a[[1]][[n]];c=a[[1]][[n+1]];If[b==1&&c==1,AppendTo[lst,n-1]],{n,8!-1}];lst (* Vladimir Joseph Stephan Orlovsky, Jun 02 2009 *)
Flatten[Position[Partition[RealDigits[Pi,10,4000][[1]],2,1],?(#=={1,1}&) ]]-1 (* _Harvey P. Dale, Dec 01 2013 *)
SequencePosition[RealDigits[Pi,10,4000][[1]],{1,1}][[;;,1]]-1 (* Harvey P. Dale, Jul 08 2024 *)

Extensions

Edited by N. J. A. Sloane, Aug 10 2010