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a(n) = A070939(3^k) - 2*A000120(3^k) with k = A372097(n).
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%I #6 May 02 2024 17:34:02

%S -1,0,1,2,4,7,8,12,15,18,25,26,30,51,75,78,84,129,133,148,170,180,183,

%T 189,209,265,279,285,287,336,369,388,406,412,445,469,496,581,711,737,

%U 741,742,873,939,994,1044,1078,1111,1157,1158,1492,1636,1767,1914,1933

%N a(n) = A070939(3^k) - 2*A000120(3^k) with k = A372097(n).

%C a(n)/2 are the negated differences at supporting points ​​of the lower envelope of the scatter band of the deviation of the binary weight of 3^k from half the length of the corresponding binary number.

%H Hugo Pfoertner, <a href="/A372098/b372098.txt">Table of n, a(n) for n = 1..99</a>

%Y Cf. A000120, A000244, A011754, A070939, A078839, A372097, A372099, A372100.

%K sign

%O 1,4

%A _Hugo Pfoertner_, Apr 25 2024