A308175 Let EM denote the Ehrenfeucht-Mycielski sequence A038219, and let P(n) = [EM(1),...,EM(n)]. To compute EM(n+1) for n>=3, we find the longest suffix S (say) of P(n) which has previously appeared in P(n). Suppose the most recent appearance of S began at index n-t(n). Then a(n) = t(n), while the length of S is given in A308174.

2, 1, 4, 1, 5, 4, 8, 4, 7, 2, 8, 12, 2, 13, 10, 17, 7, 3, 8, 19, 14, 3, 15, 21, 19, 24, 18, 28, 17, 25, 27, 19, 34, 9, 23, 7, 38, 21, 32, 20, 38, 14, 30, 34, 29, 45, 24, 39, 35, 4, 36, 41, 27, 49, 33, 54, 36, 52, 41, 4, 42, 54, 39, 31, 65, 24, 44, 9, 36, 53

Offset: 3

Author

N. J. A. Sloane, May 21 2019, corrected and extended May 21 2019

Keywords

• nonn
• look

Comments

Then EM(n+1) is the complement of the bit following the most recent appearance of S.

Examples

			Tableau showing calculation of terms 3 through 13
1   2   3   4   5   6   7   8   9  10  11  12  13  n
0   1   0   0   1   1   0   1   0   1   1   1   0  A038219(n)
-   -   0   0  01   1  10  01 010 101 011  11 110  S
-   -   1   1   2   1   2   2   3   3   3   2   3  s = A308174(n)
-   -   1   3   1   5   2   4   1   6   4  10   5  previous
-   -   2   1   4   1   5   4   8   4   7   2   8  t = A308175(n)
"Previous" = index of start of most recent previous occurrence of S; s = |S|; t = n - "previous" = A308175(n)
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 3..50000
• Rémy Sigrist, Perl program for A308175

Crossrefs

Cf. A038219, A308174.

Programs

Perl

See Links section.

Extensions

More terms from Rémy Sigrist, May 21 2019