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A255239
Alternating row sums of triangle A255238.
1
1, 1, 2, 3, 3, 4, 3, 5, 4, 7, 6, 8, 7, 10, 6, 9, 6, 11, 9, 14, 11, 15, 10, 15, 11, 14, 11, 18, 14, 19, 14, 18, 13, 20, 15, 23, 16, 25, 21, 24, 19, 23, 16, 27, 20, 28, 21, 30, 22, 27, 22, 31, 25, 34, 27, 35, 24, 35, 26, 32, 29, 36, 26, 39, 28
OFFSET
0,3
COMMENTS
See A255238 for a Gauss' circle problem comment and a link.
FORMULA
a(n) = sum((-1)^m*T(n, m), m = 0..n), n >= 0, with T(n, m) = A255238(n, m) = 1 + floor(sqrt(n^2 - m^2)).
CROSSREFS
Cf. A255238.
Sequence in context: A351085 A049878 A038203 * A316339 A186971 A329255
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Mar 12 2015
STATUS
approved