First differences of A072272.

Terms

a(0) =4a(1) =0a(2) =12a(3) =-12a(4) =20a(5) =-8a(6) =44a(7) =-56a(8) =20a(9) =0a(10) =60a(11) =-68a(12) =68a(13) =-24a(14) =156a(15) =-212a(16) =20a(17) =0a(18) =60a(19) =-60a(20) =100a(21) =-40a(22) =220a(23) =-288a(24) =68a(25) =0a(26) =204a(27) =-228a(28) =244a(29) =-88