A084145 First digit occurring consecutively at least n times in Pi's decimal expansion.

3, 3, 1, 9, 9, 9, 3, 4, 7, 6, 1, 7, 8, 9, 6, 6, 6

Offset: 1

Author

Rick L. Shepherd, May 23 2003

Keywords

• base
• nonn
• more

Comments

A simple variation on this sequence could ignore the 3 before the decimal point, making a(1)=1 instead.

Examples

			a(4)=a(5)=a(6) = 9 because there are (exactly) six consecutive 9's occurring with starting index A049522(4)=A049522(5)=A049522(6) = 763 and there are no runs of 4, 5, 6, or more consecutive equal digits having a smaller starting index.
The first occurrence of a run of at least seven consecutive equal digits occurs at starting index A049522(7) = 710101. The run consists of exactly seven 3's so a(7) = 3 [=A084144(7)] and also A049523(7) = 710101.
		

Links

• Dave Andersen, Pi-Search Page
• Timothy Mullican, 50 trillion digits of pi
• Peter Trüb, 22.4 trillion digits of pi
• Eric Weisstein's World of Mathematics, Pi Digits

Crossrefs

Cf. A049522 (starting index), A084144 (consecutively exactly n times), A049523 (starting index for A084144 runs).

Extensions

a(10)-a(14) added by Dmitry Petukhov, Jan 13 2020

a(15)-a(17) from Dmitry Petukhov, Oct 30 2021