login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A372098
a(n) = A070939(3^k) - 2*A000120(3^k) with k = A372097(n).
4
-1, 0, 1, 2, 4, 7, 8, 12, 15, 18, 25, 26, 30, 51, 75, 78, 84, 129, 133, 148, 170, 180, 183, 189, 209, 265, 279, 285, 287, 336, 369, 388, 406, 412, 445, 469, 496, 581, 711, 737, 741, 742, 873, 939, 994, 1044, 1078, 1111, 1157, 1158, 1492, 1636, 1767, 1914, 1933
OFFSET
1,4
COMMENTS
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.
LINKS
KEYWORD
sign
AUTHOR
Hugo Pfoertner, Apr 25 2024
STATUS
approved