OFFSET
1,1
COMMENTS
Each primitive 3-simplex (0,b,c,d) with b > c > d is built by 1 odd edge and 2 even edges; the edge that is considered here is the even one with the least 2-adic valuation.
LINKS
Eric Weisstein's World of Mathematics, Trirectangular Tetrahedron
CROSSREFS
KEYWORD
nonn
AUTHOR
Ralf Steiner, Jan 11 2018
STATUS
approved