a(n) is the smallest square pyramidal number with binary weight n.

Terms

a(0) =0a(1) =1a(2) =5a(3) =14a(4) =30a(5) =55a(6) =819a(7) =506a(8) =1785a(9) =1015a(10) =16206a(11) =51039a(12) =98021a(13) =81375a(14) =1113775a(15) =964535a(16) =2607099a(17) =5494655a(18) =1048061a(19) =6029275a(20) =50331190a(21) =356343295a(22) =534555645a(23) =516941815a(24) =4021378559a(25) =2143222510a(26) =12842950505a(27) =34091142526a(28) =68651299705a(29) =124545644405