

A232357


The number of pairs of numbers below n that, when generating a Fibonaccilike sequence modulo n, do not contain zero.


2



0, 0, 0, 0, 4, 0, 0, 24, 0, 16, 20, 48, 84, 0, 36, 120, 144, 144, 36, 64, 288, 80, 0, 360, 104, 336, 0, 288, 448, 144, 60, 504, 580, 864, 196, 912, 684, 792, 756, 760, 880, 1152, 0, 920, 324, 1056, 1472, 1800, 0, 416, 1296, 1344, 1404, 1440, 2504, 2040, 1620, 1792, 116, 1584, 2820, 2040, 2880
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OFFSET

1,5


COMMENTS

a(n) = 0 iff n is in A064414, a(n) is not equal to zero iff n is in A230457.


LINKS



EXAMPLE

The sequence 2,1,3,4,2,1 is the sequence of Lucas numbers modulo 5. Lucas numbers are never divisible by 5. The 4 pairs (2,1), (1,3), (3,4), (4,2) are the only pairs that can generate a sequence modulo 5 that doesn't contain zeros. Thus, a(5) = 4.
Any Fibonacci like sequence contains elements divisible by 2, 3, or 4. Thus, a(2) = a(3) = a(4) = 0.


MATHEMATICA

fibLike[list_] := Append[list, list[[1]] + list[[2]]]; Table[Count[Flatten[Table[Count[Nest[fibLike, {n, m}, k^2]/k, _Integer], {n, k1}, {m, k1}]], 0], {k, 70}]


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



