cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A177894 Determinant of the square matrix whose rows are the cyclic permutations of the digits of n.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 0, -3, -8, -15, -24, -35, -48, -63, -80, 4, 3, 0, -5, -12, -21, -32, -45, -60, -77, 9, 8, 5, 0, -7, -16, -27, -40, -55, -72, 16, 15, 12, 7, 0, -9, -20, -33, -48, -65, 25, 24, 21, 16, 9, 0, -11, -24, -39, -56, 36, 35, 32, 27, 20, 11, 0, -13, -28, -45, 49, 48, 45, 40, 33, 24, 13, 0, -15, -32, 64, 63, 60, 55, 48, 39, 28, 15, 0, -17, 81, 80, 77, 72, 65, 56, 45, 32
Offset: 0

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Author

Michel Lagneau, Dec 15 2010

Keywords

Examples

			for n=104, the (3 X 3) matrix M is
  [1 0 4]
  [0 4 1]
  [4 1 0]
and a(104) = det(M) = -65.
		

Crossrefs

Coincides with A257587 for the first 100 terms, but differs thereafter.

Programs

  • Mathematica
    A177894[n_] := If[n < 10, n, Det[NestList[RotateLeft, IntegerDigits[n], IntegerLength[n]-1]]]; Array[A177894, 100, 0] (* Paolo Xausa, Mar 11 2024 *)
  • PARI
    a(n) = {if(n<10, return(n)); my(d = digits(n), m, s); d = concat(d, d); s = #d/2; m = matrix(s, s, i, j, d[i+j-1]); matdet(m)} \\ David A. Corneth, Jun 12 2017
  • Sage
    def A177894(n):
        d = n.digits()[::-1] if n > 0 else [0]
        M = Matrix(lambda i,j: d[(i+j) % len(d)], nrows=len(d))
        return M.determinant() # D. S. McNeil, Dec 16 2010
    

Formula

For n = a, det(M) = a;
for n = ab, det(M) = a^2 - b^2;
for n = abc, det(M) = 3abc - a^3 - b^3 - c^3; ...