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

Terms

a(0) =0a(1) =0a(2) =2a(3) =2a(4) =10a(5) =10a(6) =10a(7) =74a(8) =202a(9) =202a(10) =714a(11) =714a(12) =714a(13) =714a(14) =8906a(15) =25290a(16) =58058a(17) =123594a(18) =254666a(19) =516810a(20) =516810a(21) =1565386a(22) =1565386a(23) =5759690a(24) =14148298a(25) =14148298a(26) =47702730a(27) =47702730a(28) =181920458a(29) =450355914