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A309477 One of the two successive approximations up to 3^n for the 3-adic integer sqrt(-1/2).

%I A309477 #17 Aug 04 2019 19:52:59
%S A309477 0,2,2,11,11,11,254,254,4628,11189,30872,89921,444215,444215,2038538,
%T A309477 2038538,30736352,73783073,73783073,848624051,2010885518,8984454320,
%U A309477 29905160726,61286220335,61286220335,626145293297,626145293297,3168011121626,10793608606613,33670401061574
%N A309477 One of the two successive approximations up to 3^n for the 3-adic integer sqrt(-1/2).
%H A309477 Seiichi Manyama, <a href="/A309477/b309477.txt">Table of n, a(n) for n = 0..1000</a>
%F A309477 a(n) = 3^n - A309476(n) for n > 0.
%e A309477 a(1) = (  2)_3 = 2,
%e A309477 a(2) = (  2)_3 = 2,
%e A309477 a(3) = (102)_3 = 11,
%e A309477 a(4) = (102)_3 = 11.
%o A309477 (PARI) {a(n) = if(n, 3^n-truncate(sqrt(-1/2+O(3^n))), 0)}
%Y A309477 Cf. A271222, A309475, A309476.
%K A309477 nonn
%O A309477 0,2
%A A309477 _Seiichi Manyama_, Aug 04 2019