a(n) = floor(Sum_{k=n^4..(n+1)^4} k^(1/4)).

Terms

a(0) =1a(1) =26a(2) =171a(3) =628a(4) =1685a(5) =3726a(6) =7231a(7) =12776a(8) =21033a(9) =32770a(10) =48851a(11) =70236a(12) =97981a(13) =133238a(14) =177255a(15) =231376a(16) =297041a(17) =375786a(18) =469243a(19) =579140a(20) =707301a(21) =855646a(22) =1026191a(23) =1221048a(24) =1442425a(25) =1692626a(26) =1974051a(27) =2289196a(28) =2640653a(29) =3031110