The terms of A055258 (sums of two powers of 7) divided by 2.

Terms

a(0) =1a(1) =4a(2) =7a(3) =25a(4) =28a(5) =49a(6) =172a(7) =175a(8) =196a(9) =343a(10) =1201a(11) =1204a(12) =1225a(13) =1372a(14) =2401a(15) =8404a(16) =8407a(17) =8428a(18) =8575a(19) =9604a(20) =16807a(21) =58825a(22) =58828a(23) =58849a(24) =58996a(25) =60025a(26) =67228a(27) =117649a(28) =411772a(29) =411775