Convolution of A007528 and A002476.

Terms

a(0) =35a(1) =142a(2) =357a(3) =746a(4) =1351a(5) =2250a(6) =3533a(7) =5248a(8) =7467a(9) =10232a(10) =13675a(11) =17910a(12) =22979a(13) =28972a(14) =35931a(15) =44192a(16) =53677a(17) =64392a(18) =76727a(19) =90640a(20) =106209a(21) =123614a(22) =142849a(23) =164232a(24) =187841a(25) =213802a(26) =242181a(27) =273080a(28) =306733a(29) =343266