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A309476 One of the two successive approximations up to 3^n for the 3-adic integer sqrt(-1/2). 3

%I #14 May 11 2020 01:04:58

%S 0,1,7,16,70,232,475,1933,1933,8494,28177,87226,87226,1150108,2744431,

%T 12310369,12310369,55357090,313637416,313637416,1475898883,1475898883,

%U 1475898883,32856958492,221143316146,221143316146,1915720535032,4457586363361,12083183848348,34959976303309

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

%H Robert Israel, <a href="/A309476/b309476.txt">Table of n, a(n) for n = 0..2093</a>

%e a(1) = ( 1)_3 = 1,

%e a(2) = ( 21)_3 = 7,

%e a(3) = ( 121)_3 = 16,

%e a(4) = (2121)_3 = 70.

%p N:= 30: # for a(0) to a(N)

%p with(padic):

%p A:= rootp(x^2+1/2,3,N):

%p if ratvaluep(A[1],1) = 1 then A:= A[1] else A:= A[2] fi:

%p seq(ratvaluep(A,i),i=0..N); # _Robert Israel_, May 11 2020

%o (PARI) {a(n) = truncate(sqrt(-1/2+O(3^n)))}

%Y Cf. A268924, A309474, A309477.

%K nonn

%O 0,3

%A _Seiichi Manyama_, Aug 04 2019

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Last modified April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)