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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

See A255238 for a Gauss' circle problem comment and a link.

LINKS

Table of n, a(n) for n=0..64.

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: A140605 A049878 A038203 * A316339 A186971 A329255

Adjacent sequences:  A255236 A255237 A255238 * A255240 A255241 A255242

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang, Mar 12 2015

STATUS

approved

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Last modified February 25 11:17 EST 2020. Contains 332234 sequences. (Running on oeis4.)