A373079 Decimal digits of Pi selected by stepping forward d places at digit d or 10 places if d=0.

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

Offset

1,1

Comments

Are the digits uniformly distributed?

Links

Table of n, a(n) for n=1..100.

Formula

a(n) = the (1 + Sum_{i=1..n-1} a(i) + 10*delta(a(i),0))-th digit in the decimal expansion of Pi, where delta is the Kronecker symbol.

Example

The sequence starts with the first digit of the decimal expansion of Pi, which is 3. The next term is the digit 3 places after this, namely, 1, and so on.
The digits selected from Pi begin
  Pi = 3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5, 8, 9, ...
       ^        ^  ^              ^        ^

Mathematica

a={3}; s=1; For[n=2, n<=100, n++, s+=Part[a, n-1]+10KroneckerDelta[Part[a, n-1]]; digits=First[RealDigits[Pi, 10, s]]; AppendTo[a, Part[digits, s]]]; a (* Stefano Spezia, May 31 2024 *)

Crossrefs

Cf. A000796,

Cf. A373304, A373307.

Sequence in context: A318726 A333871 A364034 * A212641 A195835 A077881

Adjacent sequences: A373076 A373077 A373078 * A373080 A373081 A373082

Keyword

nonn,base,cons

Author

Karl Levy, May 22 2024

Extensions

a(25)-a(100) from Stefano Spezia, May 31 2024

Status

approved