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A048152
Triangular array T read by rows: T(n,k) = k^2 mod n, for 1 <= k <= n, n >= 1.
18
0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 4, 4, 1, 0, 1, 4, 3, 4, 1, 0, 1, 4, 2, 2, 4, 1, 0, 1, 4, 1, 0, 1, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0, 1, 4, 9, 5, 3, 3, 5, 9, 4, 1, 0, 1, 4, 9, 4, 1, 0, 1, 4, 9, 4, 1, 0, 1, 4, 9, 3, 12, 10, 10, 12, 3, 9, 4, 1, 0
OFFSET
1,12
LINKS
Eric Weisstein's World of Mathematics, Quadratic Residue
FORMULA
T(n,k) = A133819(n,k) mod n, k = 1..n. - Reinhard Zumkeller, Apr 29 2013
T(n,k) = (T(n,k-1) + (2k+1)) mod n. - Andrés Ventas, Apr 06 2021
EXAMPLE
Rows:
0;
1, 0;
1, 1, 0;
1, 0, 1, 0;
1, 4, 4, 1, 0;
1, 4, 3, 4, 1, 0;
MATHEMATICA
Flatten[Table[PowerMod[k, 2, n], {n, 15}, {k, n}]] (* Harvey P. Dale, Jun 20 2011 *)
PROG
(Haskell)
a048152 n k = a048152_tabl !! (n-1) !! (k-1)
a048152_row n = a048152_tabl !! (n-1)
a048152_tabl = zipWith (map . flip mod) [1..] a133819_tabl
-- Reinhard Zumkeller, Apr 29 2013
CROSSREFS
Cf. A060036.
Cf. A225126 (central terms).
Cf. A070430 (row 5), A070431 (row 6), A053879 (row 7), A070432 (row 8), A008959 (row 10), A070435 (row 12), A070438 (row 15), A070422 (row 20).
Cf. A046071 (in ascending order, without zeros and duplicates).
Cf. A063987 (for primes, in ascending order, without zeros and duplicates).
Sequence in context: A373749 A185057 A343720 * A350037 A070430 A336302
KEYWORD
nonn,tabl,nice,easy
STATUS
approved