Lower triangular array called S1hat(4) related to partition number array A144885.

Terms

a(0) =1a(1) =4a(2) =1a(3) =20a(4) =4a(5) =1a(6) =120a(7) =36a(8) =4a(9) =1a(10) =840a(11) =200a(12) =36a(13) =4a(14) =1a(15) =6720a(16) =1720a(17) =264a(18) =36a(19) =4a(20) =1a(21) =60480a(22) =12480a(23) =2040a(24) =264a(25) =36a(26) =4a(27) =1a(28) =604800a(29) =118560