A175466 Table read by antidiagonals: a(m,n) = the largest positive integer occurring, when written in binary, as a substring in both binary m and binary n.
1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 3, 2, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 4, 1, 2, 1, 1, 1, 3, 2, 2, 3, 1, 1, 1, 2, 3, 2, 5, 2, 3, 2, 1, 1, 2, 1, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 4, 1, 6, 1, 4, 1, 2, 1, 1, 2, 1, 4, 2, 3, 3, 2, 4, 1, 2, 1, 1, 2, 3, 2, 2, 2, 7, 2, 2
Offset: 1
Examples
From _Rémy Sigrist_, Jul 20 2019: (Start) Table a(n, k) begins (in decimal): n\k| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ---+--------------------------------------------------- 1| 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2| 1 2 1 2 2 2 1 2 2 2 2 2 2 2 1 3| 1 1 3 1 1 3 3 1 1 1 3 3 3 3 3 4| 1 2 1 4 2 2 1 4 4 2 2 4 2 2 1 5| 1 2 1 2 5 2 1 2 2 5 5 2 5 2 1 6| 1 2 3 2 2 6 3 2 2 2 3 6 6 6 3 7| 1 1 3 1 1 3 7 1 1 1 3 3 3 7 7 8| 1 2 1 4 2 2 1 8 4 2 2 4 2 2 1 9| 1 2 1 4 2 2 1 4 9 2 2 4 2 2 1 10| 1 2 1 2 5 2 1 2 2 10 5 2 5 2 1 11| 1 2 3 2 5 3 3 2 2 5 11 3 5 3 3 12| 1 2 3 4 2 6 3 4 4 2 3 12 6 6 3 13| 1 2 3 2 5 6 3 2 2 5 5 6 13 6 3 14| 1 2 3 2 2 6 7 2 2 2 3 6 6 14 7 15| 1 1 3 1 1 3 7 1 1 1 3 3 3 7 15 Table a(n, k) begins (in binary): n\k| 1 10 11 100 101 110 111 1000 1001 1010 1011 1100 1101 1110 1111 ----+---------------------------------------------------------------- 1| 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10| 1 10 1 10 10 10 1 10 10 10 10 10 10 10 1 11| 1 1 11 1 1 11 11 1 1 1 11 11 11 11 11 100| 1 10 1 100 10 10 1 100 100 10 10 100 10 10 1 101| 1 10 1 10 101 10 1 10 10 101 101 10 101 10 1 110| 1 10 11 10 10 110 11 10 10 10 11 110 110 110 11 111| 1 1 11 1 1 11 111 1 1 1 11 11 11 111 111 1000| 1 10 1 100 10 10 1 1000 100 10 10 100 10 10 1 1001| 1 10 1 100 10 10 1 100 1001 10 10 100 10 10 1 1010| 1 10 1 10 101 10 1 10 10 1010 101 10 101 10 1 1011| 1 10 11 10 101 11 11 10 10 101 1011 11 101 11 11 1100| 1 10 11 100 10 110 11 100 100 10 11 1100 110 110 11 1101| 1 10 11 10 101 110 11 10 10 101 101 110 1101 110 11 1110| 1 10 11 10 10 110 111 10 10 10 11 110 110 1110 111 1111| 1 1 11 1 1 11 111 1 1 1 11 11 11 111 1111 (End)
Links
- Rémy Sigrist, Table of n, a(n) for n = 1..11325
- Rémy Sigrist, Colored representation of the table for n = 1..1023 and k = 1023
Programs
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PARI
sub(n) = { my (b=binary(n), s=[]); for (i=1, #b, if (b[i], for (j=i, #b, s=setunion(s, Set(fromdigits(b[i..j], 2)))))); return (s) } T(n,k) = my (i=setintersect(sub(n), sub(k))); i[#i] \\ Rémy Sigrist, Jul 20 2019
Formula
From Rémy Sigrist, Jul 20 2019: (Start)
1 <= a(n, k) <= min(n, k).
a(n, k) = a(k, n).
a(n, n) = n.
a(n, 1) = 1.
a(n, 2) = A043529(n).
a(n, 3) = 3 iff n belongs to A004780. (End)
Extensions
More terms from Rémy Sigrist, Jul 20 2019
Comments