A347835 - OEIS

%I #15 Sep 30 2021 22:15:17

%S 2,3,10,6,11,9,94,5,14,50,18,51,8,23,70,22,1,30,32,80,36,60,35,13,28,

%T 34,17,38,380,47,57,90,4,21,20,43,45,7,79,54,12,76,81,949,84,91,41,56,

%U 590,120,15,39,49,25,24,99,68,53,101,59,64,71,106,26,44,29,69,77,16,89,66,33,108,31,82,117,42

%N Lexicographically earliest sequence of distinct terms > 0 such that the a(a(n))-th digit of S is the n-th digit of Pi.

%e The  2nd digit of S is 3 and if n = 1 then a(1) =  2 and a(a(1)) = 3.

%e The  3rd digit of S is 1 and if n = 2 then a(2) =  3 and a(a(2)) = 1.

%e The 10th digit of S is 4 and if n = 3 then a(3) = 10 and a(a(3)) = 4.

%e The  6th digit of S is 1 and if n = 4 then a(4) =  6 and a(a(4)) = 1.

%e The 11th digit of S is 5 and if n = 5 then a(5) = 11 and a(a(5)) = 5.

%e The  9th digit of S is 9 and if n = 6 then a(6) = 94 and a(a(6)) = 9.

%e The 94th digit of S is 2 and if n = 7 then a(7) =  5 and a(a(7)) = 2, etc.

%e We see above that the leftmost column of integers forms the sequence S and the rightmost column of digits forms the successive digits of Pi.

%Y Cf. A000796.

%K base,nonn

%O 1,1

%A _Eric Angelini_ and _Carole Dubois_, Sep 21 2021