Number of pairs of sequences of cardinality at least 2.
A052520
Number of pairs of sequences of cardinality at least 2.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =24a(5) =240a(6) =2160a(7) =20160a(8) =201600a(9) =2177280a(10) =25401600a(11) =319334400a(12) =4311014400a(13) =62270208000a(14) =958961203200
External references
- oeis: A052520