Engel expansion of Sum_{k>=0} 1/(3 + k)^k.

Terms

a(0) =1a(1) =4a(2) =6a(3) =13a(4) =16a(5) =31a(6) =131a(7) =231a(8) =578a(9) =905a(10) =1649a(11) =4810a(12) =5999a(13) =10249a(14) =11962a(15) =21338a(16) =229345a(17) =404066a(18) =772217a(19) =1646462a(20) =2129025a(21) =235494066a(22) =559730937a(23) =1287457726a(24) =1549953698a(25) =2919657850a(26) =23892156516a(27) =52085560558a(28) =70347157214