Variation of Stechkin's function, A055004.

Terms

a(0) =0a(1) =4a(2) =15a(3) =45a(4) =116a(5) =259a(6) =505a(7) =853a(8) =1378a(9) =2256a(10) =3249a(11) =4855a(12) =6730a(13) =8738a(14) =11348a(15) =15012a(16) =19533a(17) =23693a(18) =29693a(19) =35876a(20) =41890a(21) =50691a(22) =59467a(23) =70667a(24) =84999a(25) =97916a(26) =110050a(27) =124679a(28) =138413a(29) =155289