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A357724
Triangular array read by rows: T(n,k) = Fib(n) mod Fib(k) for 1 <= k <= n, where Fib(k) = A000045(k).
2
0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 2, 0, 0, 0, 0, 2, 3, 0, 0, 0, 1, 1, 3, 5, 0, 0, 0, 1, 0, 1, 5, 8, 0, 0, 0, 0, 1, 4, 2, 8, 13, 0, 0, 0, 1, 1, 0, 7, 3, 13, 21, 0, 0, 0, 1, 2, 4, 1, 11, 5, 21, 34, 0, 0, 0, 0, 0, 4, 0, 1, 18, 8, 34, 55, 0, 0, 0, 1, 2, 3, 1, 12, 2, 29, 13, 55, 89, 0, 0, 0, 1, 2
OFFSET
1,14
COMMENTS
For k > 2, T(n,k) = 0 if and only if n is divisible by k. Otherwise, let n = q*k+r with 0 < r < k and k > 2.
If q is even and k is even, or q == 0 (mod 4) and k is odd, T(n,k) = A000045(r).
If q == 2 (mod 4) and k is odd, T(n,k) = A000045(k) - A000045(r).
If q == 1 (mod 4) and r is odd, or q == 3 (mod 4) and r+k is odd, T(n,k) = A000045(k-r).
If q == 1 (mod 4) and r is even, or q == 3 (mod 4) and r+k is even, T(n,k) = A000045(k) - A000045(k-r).
LINKS
Robert Israel, Table of n, a(n) for n = 1..10011 (rows 1 to 141, flattened)
EXAMPLE
Triangle starts:
0;
0, 0;
0, 0, 0;
0, 0, 1, 0;
0, 0, 1, 2, 0;
0, 0, 0, 2, 3, 0;
0, 0, 1, 1, 3, 5, 0;
0, 0, 1, 0, 1, 5, 8, 0;
0, 0, 0, 1, 4, 2, 8, 13, 0;
0, 0, 1, 1, 0, 7, 3, 13, 21, 0;
0, 0, 1, 2, 4, 1, 11, 5, 21, 34, 0;
MAPLE
fib:= combinat:-fibonacci:
for n from 1 to 20 do
seq(fib(n) mod fib(k), k=1..n)
od;
CROSSREFS
Sequence in context: A342563 A343633 A174469 * A297934 A112166 A112167
KEYWORD
nonn,look,tabl
AUTHOR
J. M. Bergot and Robert Israel, Oct 12 2022
STATUS
approved