Half the number of 4X4 0..n symmetric arrays with no 2X2 subblock summing to 2n.
A213699
Half the number of 4X4 0..n symmetric arrays with no 2X2 subblock summing to 2n.
Terms
- a(0) =70a(1) =7827a(2) =208072a(3) =2322599a(4) =16537086a(5) =84059234a(6) =342943680a(7) =1169405354a(8) =3500184570a(9) =9372540629a(10) =23022951048a(11) =52423261153a(12) =112270651514a(13) =227577256564a(14) =440658095360a(15) =818409534692
External references
- oeis: A213699