A084144 First digit occurring consecutively exactly n times in Pi's decimal expansion.
3, 3, 1, 7, 0, 9, 3, 4, 7, 6, 1, 7, 8, 9, 6
Offset: 1
Examples
a(3) = 1 because the digit string <8>111<7>, where n=3, d=1, d1=8<>1 and d2=7<>1 in the following general form, occurs in the decimal expansion of Pi with a smaller starting index than all occurrences for n=3 of the string <d1>dd...d (n d's)<d2> for d=0, 2, 3, ..., or 9, where all of these n-digit strings are immediately preceded by some d1<>d and followed by some d2<>d. A049523(3) = 154 gives the starting index of this first occurrence of exactly three consecutive equal digits; i.e. the first 1 in this 111 is the 154th digit of Pi counting the 3 before the decimal point - add 1 to Pi-Search page result - but ignoring the decimal point itself. (<d1> is of course not completely applicable for the case n=1 in determining a(1).)
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.
Extensions
a(10)-a(11) from Giovanni Resta, Oct 02 2019
a(12)-a(14) added by Dmitry Petukhov, Jan 13 2020
a(15) from Dmitry Petukhov, Oct 30 2021
Comments