Second differences of A000463; first differences of A188652.

Terms

a(0) =1a(1) =1a(2) =-3a(3) =7a(4) =-11a(5) =17a(6) =-23a(7) =31a(8) =-39a(9) =49a(10) =-59a(11) =71a(12) =-83a(13) =97a(14) =-111a(15) =127a(16) =-143a(17) =161a(18) =-179a(19) =199a(20) =-219a(21) =241a(22) =-263a(23) =287a(24) =-311a(25) =337a(26) =-363a(27) =391a(28) =-419a(29) =449