Number of (n+1)X(n+1) -5..5 symmetric matrices with every 2X2 subblock having sum zero and three or four distinct values.
A211334
Number of (n+1)X(n+1) -5..5 symmetric matrices with every 2X2 subblock having sum zero and three or four distinct values.
Terms
- a(0) =46a(1) =194a(2) =802a(3) =3322a(4) =13754a(5) =57170a(6) =238650a(7) =1001306a(8) =4222530a(9) =17893954a(10) =76173162a(11) =325583338a(12) =1396612370a(13) =6009460210a(14) =25926690010a(15) =112107619226a(16) =485673993154
External references
- oeis: A211334