Triangle of numbers related to A000330 (sum of squares) and A000364 (Euler numbers).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =5a(5) =5a(6) =1a(7) =14a(8) =61a(9) =61a(10) =1a(11) =30a(12) =331a(13) =1385a(14) =1385a(15) =1a(16) =55a(17) =1211a(18) =12284a(19) =50521a(20) =50521a(21) =1a(22) =91a(23) =3486a(24) =68060a(25) =663061a(26) =2702765a(27) =2702765a(28) =1a(29) =140