A283714 a(n) is the first occurrence after a(n-1) of the n-th digit in the decimal expansion of Pi-3, beginning with a(0)=1.

1, 3, 19, 37, 48, 55, 63, 69, 90, 91, 109, 113, 122, 139, 144, 170, 173, 194, 197, 201, 211, 221, 226, 227, 230, 231, 233, 237, 241, 242, 247, 252, 264, 275, 279, 305, 321, 324, 328, 343, 344, 347, 353, 358, 388, 391, 401, 405, 411, 417, 421, 444, 447, 456, 493, 496, 506, 511, 527, 528, 530, 534, 542

Offset: 0

Author

Christian Perfect, Mar 15 2017

Keywords

• nonn
• base
• easy

Comments

Skip the first decimal digit of Pi, and then look for the first occurrence of each of the digits in order, only moving forward.

This sequence arose as a result of the claim that the digits of Pi appear in order again later on, if you allow gaps between subsequent digits.

a(n) ~ 10n. - Robert G. Wilson v, Mar 15 2017

Examples

			a(1) = 3, because the first occurrence of the first decimal digit of Pi after the first decimal digit is at the 3rd decimal digit.
a(2) = 19, because the next occurrence of the second decimal digit of Pi after the 3rd decimal digit is at the 19th decimal digit.
		

Links

• Robert G. Wilson v, Table of n, a(n) for n = 0..10000 (corrected by Ray Chandler, Jan 19 2019)

Crossrefs

Cf. A000796.

Programs

Mathematica

pid = RealDigits[Pi - 3, 10, 10000][[1]]; a[0] = 1; a[n_] := a[n] = SelectFirst[ Flatten[ Position[ pid, pid[[n]], 1, 200]], a[n -1] < # &]; Array[a, 100] (* Robert G. Wilson v, Mar 15 2017 *)