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A212241 Number of 2 X 2 matrices M of with terms in {1,...,n} such that permanent(M) > n. 2
0, 1, 15, 76, 243, 598, 1249, 2326, 3984, 6405, 9786, 14363, 20378, 28117, 37864, 49965, 64740, 82591, 103877, 129062, 158543, 192832, 232371, 277740, 329399, 388002, 454043, 528220, 611087, 703402, 805721, 918898, 1043520, 1180469 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

A212241(n) + A212151(n+1) = n^4.  For a guide to related sequences, see A211795.

LINKS

Table of n, a(n) for n=0..33.

MATHEMATICA

t = Compile[{{n, _Integer}}, Module[{s = 0},

(Do[If[w*x + y*z > n, s = s + 1],

{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];

Map[t[#] &, Range[0, 40]]  (* A212241 *)

(* Peter J. C. Moses, Apr 13 2012 *)

CROSSREFS

Cf. A211795.

Sequence in context: A049391 A247264 A212093 * A000477 A302376 A041430

Adjacent sequences:  A212238 A212239 A212240 * A212242 A212243 A212244

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 08 2012

STATUS

approved

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Last modified September 24 14:16 EDT 2021. Contains 347643 sequences. (Running on oeis4.)