A108535 Positions of balanced digits in the decimal expansion of Pi.

5, 155, 173, 179, 210, 236, 253, 262, 274, 275, 293, 352, 353, 359, 390, 410, 468, 603, 636, 654, 661, 674, 696, 703, 723, 732, 764, 765, 766, 767, 780, 796, 804, 822, 836, 857, 875, 885, 897, 918, 924, 961, 981, 985, 995, 996, 1015, 1059, 1200, 1234, 1246

Offset

1,1

Comments

Cf. A108533 (strong digits), A108534 (weak digits). In the decimal expansion of Pi, balanced digits are much more rare than weak or strong ones.

Links

Table of n, a(n) for n=1..51.

Mathematica

re=RealDigits[N[Pi, 2900]][[1]]; b={}; Do[r=re[[n]]; If[r==(re[[n-1]]+re[[n+1]])/2, b=Append[b, r]], {n, 2, 2899}]; A108535=b
With[{pid=RealDigits[Pi, 10, 1300][[1]]}, Flatten[Position[Partition[ pid, 3, 1], _?((#[[1]]+#[[3]])/2==#[[2]]&), 1, Heads->False]]]+1 (* Harvey P. Dale, Apr 30 2019 *)

Crossrefs

Cf. A108533, A108534.

Sequence in context: A222768 A208578 A322634 * A265123 A237527 A015019

Adjacent sequences: A108532 A108533 A108534 * A108536 A108537 A108538

Keyword

nonn,base

Author

Zak Seidov, Jun 08 2005

Status

approved