Number of ways of writing n as a sum of n+1 squares.

Terms

a(0) =1a(1) =4a(2) =12a(3) =32a(4) =90a(5) =312a(6) =1288a(7) =5504a(8) =22608a(9) =88660a(10) =339064a(11) =1297056a(12) =5043376a(13) =19975256a(14) =80027280a(15) =321692928a(16) =1291650786a(17) =5177295432a(18) =20748447108a(19) =83279292960a(20) =335056780464