An interleaved sequence of pyramidal and polygonal numbers.

Terms

a(0) =0a(1) =1a(2) =1a(3) =5a(4) =6a(5) =16a(6) =20a(7) =40a(8) =50a(9) =85a(10) =105a(11) =161a(12) =196a(13) =280a(14) =336a(15) =456a(16) =540a(17) =705a(18) =825a(19) =1045a(20) =1210a(21) =1496a(22) =1716a(23) =2080a(24) =2366a(25) =2821a(26) =3185a(27) =3745a(28) =4200a(29) =4880