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A115221
Number of 3 X 3 matrices over Z(n) having determinant 0.
2
1, 344, 8451, 100864, 465125, 2907144, 6569479, 27557888, 59895369, 160003000, 233671691, 852401664, 878081581, 2259900776, 3930771375
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OFFSET
1,2
LINKS
Table of n, a(n) for n=1..15.
FORMULA
a(n)=n^9-
A115222
(n). For prime n, a(n)=n^3 (n^5+n^4-n^2-n+1)
MATHEMATICA
Table[cnt=0; Do[m={{a, b, c}, {d, e, f}, {g, h, i}}; If[Det[m, Modulus->n]==0, cnt++ ], {a, 0, n-1}, {b, 0, n-1}, {c, 0, n-1}, {d, 0, n-1}, {e, 0, n-1}, {f, 0, n-1}, {g, 0, n-1}, {h, 0, n-1}, {i, 0, n-1}]; cnt, {n, 2, 7}]
CROSSREFS
Sequence in context:
A262791
A186935
A340173
*
A065499
A183673
A231028
Adjacent sequences:
A115218
A115219
A115220
*
A115222
A115223
A115224
KEYWORD
mult
,
nonn
AUTHOR
T. D. Noe
, Jan 16 2006
STATUS
approved
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Last modified April 25 01:06 EDT 2024. Contains 371964 sequences. (Running on oeis4.)