A210288 Number of 2 X 2 matrices with all elements in {0,1,...,n} and permanent = trace.

1, 6, 19, 29, 41, 51, 65, 75, 89, 101, 115, 125, 143, 153, 167, 181, 197, 207, 225, 235, 253, 267, 281, 291, 313, 325, 339, 353, 371, 381, 403, 413, 431, 445, 459, 473, 497, 507, 521, 535, 557, 567, 589, 599, 617, 635

Offset: 0

Author

Clark Kimberling, Mar 19 2012

Keywords

• nonn

Comments

See A210000 for a guide to related sequences.

Links

• Chai Wah Wu, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A210000.

Programs

Mathematica

a = 0; b = n; z1 = 45;
t[n_] := t[n] = Flatten[Table[w + z - w*z - x*y, {w, a, b}, {x, a, b}, {y, a, b}, {z, a, b}]]
c[n_, k_] := c[n, k] = Count[t[n], k]
Table[c[n, 0], {n, 0, z1}]   (* A210288 *)