Number of 0..n arrays x(0..3) of 4 elements without any two consecutive increases.

Terms

a(0) =16a(1) =75a(2) =225a(3) =530a(4) =1071a(5) =1946a(6) =3270a(7) =5175a(8) =7810a(9) =11341a(10) =15951a(11) =21840a(12) =29225a(13) =38340a(14) =49436a(15) =62781a(16) =78660a(17) =97375a(18) =119245a(19) =144606a(20) =173811a(21) =207230a(22) =245250a(23) =288275a(24) =336726a(25) =391041a(26) =451675a(27) =519100a(28) =593805a(29) =676296