%I A039623
%S A039623 1,7,27,76,175,351,637,1072,1701,2575,3751,5292,7267,9751,12825,16576,
%T A039623 21097,26487,32851,40300,48951,58927,70357,83376,98125,114751,133407,
%U A039623 154252,177451,203175,231601,262912,297297,334951,376075,420876,469567
%N A039623 Consider a figure like this <> (a squashed square, symmetric about both 
               axes); each side is given 1 of n colors; a(n) = number of possibilities, 
               allowing turning over.
%C A039623 2 X 2 matrices with entries mod n, up to row and column permutation. 
               Number of k X l matrices with entries mod n, up to row and column 
               permutation is Z(S_k X S_l; n,n,...) where Z(S_k X S_l; x_1,x_2,...) 
               is cycle index of Cartesian product of symmetric groups S_k and S_l 
               of degree k and l, respectively - Vladeta Jovovic (vladeta(AT)eunet.rs), 
               Nov 04 2000
%C A039623 If a 2-set Y and a 3-set Z are disjoint subsets of an n-set X then a(n-5) 
               is the number of 6-subsets of X intersecting both Y and Z. - Milan 
               R. Janjic (agnus(AT)blic.net), Sep 08 2007
%D A039623 J.-P. Delahaye, 'Le miraculeux "lemme de Burnside"','Le matelas a k couleurs' 
               pp 145-6 in 'Pour la Science' (French edition of 'Scientific American') 
               No.350 December 2006 Paris.
%H A039623 Milan Janjic, <a href="http://www.pmfbl.org/janjic/">Two Enumerative 
               Functions</a>
%F A039623 a(n)=(1/4)*n^2*(n^2+3).
%e A039623 a(1)=1, a(4)=76.
%Y A039623 Cf. A058001-A058004, A002724, A052271, A052272, A005353.
%Y A039623 Sequence in context: A098931 A143690 A007715 this_sequence A005585 A027180 
               A036597
%Y A039623 Adjacent sequences: A039620 A039621 A039622 this_sequence A039624 A039625 
               A039626
%K A039623 easy,nonn,nice
%O A039623 1,2
%A A039623 Christian Meland (christian.meland(AT)pfi.no)
%E A039623 More terms from Sam Alexander (pink2001x(AT)hotmail.com)