Number of n X 4 nonnegative integer arrays each row and column an ascent sequence (interior element no greater than one plus up-steps preceding it) and the lower right element equal to min(n,4)-1.
A202731
Number of n X 4 nonnegative integer arrays each row and column an ascent sequence (interior element no greater than one plus up-steps preceding it) and the lower right element equal to min(n,4)-1.
Terms
- a(0) =1a(1) =4a(2) =14a(3) =12a(4) =462a(5) =10296a(6) =184848a(7) =3010632a(8) =46867734a(9) =714602604a(10) =10794487872a(11) =162393700356
External references
- oeis: A202731