Inverse of a triangle of pyramidal numbers.

Terms

a(0) =1a(1) =-3a(2) =1a(3) =7a(4) =-4a(5) =1a(6) =-15a(7) =11a(8) =-5a(9) =1a(10) =31a(11) =-26a(12) =16a(13) =-6a(14) =1a(15) =-63a(16) =57a(17) =-42a(18) =22a(19) =-7a(20) =1a(21) =127a(22) =-120a(23) =99a(24) =-64a(25) =29a(26) =-8a(27) =1a(28) =-255a(29) =247