Squarefree tetrahedral numbers.

Terms

a(0) =1a(1) =10a(2) =35a(3) =165a(4) =286a(5) =455a(6) =969a(7) =1330a(8) =1771a(9) =4495a(10) =6545a(11) =7770a(12) =9139a(13) =12341a(14) =14190a(15) =16215a(16) =23426a(17) =32509a(18) =35990a(19) =39711a(20) =47905a(21) =52394a(22) =57155a(23) =79079a(24) =98770a(25) =105995a(26) =121485a(27) =129766a(28) =138415a(29) =176851