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%I #23 Mar 08 2023 16:20:05
%S 0,0,1,5,16,39,80,155,281,476,760,1154,1686,2394,3331,4551,6110,8065,
%T 10486,13461,17079,21430,26606,32726,39928,48360,58183,69573,82708,
%U 97767,114930,134387,156329,180960,208506,239230,273444,311486,353709,400467,452136,509093,571716,640393,715537
%N Number of regular tetrahedra in an n-node-per-edge tetrahedral grid.
%C Number of ways to choose 4 points forming a regular tetrahedron out of the binomial(n+2,3) points in a regular tetrahedral grid.
%C The tetrahedra defined by the four points may have any orientation.
%C Similar to A216173, which differs from the present sequence in a mysterious way.
%F It would be nice to have a g.f. - _N. J. A. Sloane_, Mar 21 2016
%Y Cf. A000332 (2-D version), A216173, A270805, A270806.
%K nonn
%O 0,4
%A _Warren D. Smith_, Mar 21 2016; more terms Mar 23 2016
%E a(21) changed from 24130 to 21430 by _Anthony Guttmann_, Mar 07 2023
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