Partial sums of A007587.

Terms

a(0) =1a(1) =14a(2) =60a(3) =170a(4) =385a(5) =756a(6) =1344a(7) =2220a(8) =3465a(9) =5170a(10) =7436a(11) =10374a(12) =14105a(13) =18760a(14) =24480a(15) =31416a(16) =39729a(17) =49590a(18) =61180a(19) =74690a(20) =90321a(21) =108284a(22) =128800a(23) =152100a(24) =178425a(25) =208026a(26) =241164a(27) =278110a(28) =319145a(29) =364560