a(n) = 25 + floor( Sum_{j=1..n-1} a(j)/2 ).

Terms

a(0) =25a(1) =37a(2) =56a(3) =84a(4) =126a(5) =189a(6) =283a(7) =425a(8) =637a(9) =956a(10) =1434a(11) =2151a(12) =3226a(13) =4839a(14) =7259a(15) =10888a(16) =16332a(17) =24498a(18) =36747a(19) =55121a(20) =82681a(21) =124022a(22) =186033a(23) =279049a(24) =418574a(25) =627861a(26) =941791a(27) =1412687a(28) =2119030a(29) =3178545