Approximation of the 2-adic integer arctanh(2) up to 2^n.

Terms

a(0) =0a(1) =0a(2) =2a(3) =2a(4) =10a(5) =26a(6) =58a(7) =122a(8) =122a(9) =122a(10) =122a(11) =1146a(12) =1146a(13) =5242a(14) =13434a(15) =29818a(16) =29818a(17) =95354a(18) =95354a(19) =95354a(20) =619642a(21) =619642a(22) =619642a(23) =4813946a(24) =4813946a(25) =21591162a(26) =21591162a(27) =21591162a(28) =21591162a(29) =290026618