A175813 Numbers n such that the first n decimal digits of Pi contain equal numbers of even and odd decimal digits.

84, 576, 578, 580, 582, 646, 654, 682, 684, 686, 688, 690, 692, 694, 696, 698, 700, 702, 706, 722, 736, 740, 742, 2406, 2408, 2414, 2416, 2430, 2432, 2438, 2440, 2502, 2504, 2506, 2512, 2514, 2516, 2518, 2522, 2524, 2540, 2542, 2546, 2548, 2756, 2758, 2762

Offset

1,1

Comments

Is this sequence infinite?

Links

Harvey P. Dale, Table of n, a(n) for n = 1..459 (* The highest term in this b-file is 905564 and there are no further terms up to and including the 5 millionth digit of Pi. *)

Example

84 is in the sequence because the first 84 digits of Pi = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986 include 42 odd digits and 42 even digits.

Mathematica

L= Rest@FoldList[ Plus, 0, (-1)^First@ RealDigits[Pi, 10, 3000]] ; Do[If [L[[n]]==0, Print[n]], {n, 3000}]
Position[Accumulate[If[EvenQ[#], 1, -1]&/@(RealDigits[Pi, 10, 3000][[1]])], 0]//Flatten (* Harvey P. Dale, Jan 10 2024 *)

Crossrefs

Cf. A175792.

Sequence in context: A233053 A220203 A008429 * A238523 A238518 A264654

Adjacent sequences: A175810 A175811 A175812 * A175814 A175815 A175816

Keyword

nonn,base

Author

Michel Lagneau, Sep 09 2010

Status

approved