a(n) = Sum_{k=1..n^2} A078446(k).

Terms

a(0) =1a(1) =7a(2) =26a(3) =78a(4) =211a(5) =537a(6) =1312a(7) =3112a(8) =7217a(9) =16443a(10) =36934a(11) =82002a(12) =180319a(13) =393325a(14) =852092a(15) =1835148a(16) =3932317a(17) =8388783a(18) =17825986a(19) =37748950a(20) =79692011a(21) =167772417a(22) =352321816a(23) =738197808a(24) =1543504201a(25) =3221225827a(26) =6710886782a(27) =13958644122