a(n) =60*sum(1<=u<=v<=w<=m,u^2*v^2/w).

Terms

a(0) =0a(1) =60a(2) =690a(3) =3630a(4) =13035a(5) =37059a(6) =89839a(7) =193879a(8) =382834a(9) =704694a(10) =1225368a(11) =2032668a(12) =3240693a(13) =4994613a(14) =7475853a(15) =10907677a(16) =15561172a(17) =21761632a(18) =29895342a(19) =40416762a(20) =53856111a(21) =70827351a(22) =92036571a(23) =118290771a(24) =150507046a(25) =189722170a(26) =237102580