Sum of the digits of the n-th Mersenne prime (A000668).

Terms

a(0) =3a(1) =7a(2) =4a(3) =10a(4) =19a(5) =13a(6) =28a(7) =46a(8) =73a(9) =112a(10) =139a(11) =154a(12) =697a(13) =847a(14) =1675a(15) =3106a(16) =3106a(17) =4258a(18) =5755a(19) =5950a(20) =13216a(21) =13693a(22) =14980a(23) =27202a(24) =28939a(25) =31339a(26) =60337a(27) =116455a(28) =149365a(29) =179488