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A224931 Number of integer parallelograms with integer side lengths n = a >= b and integer diagonal lengths e >= f. 2
0, 0, 0, 1, 1, 0, 2, 1, 2, 2, 3, 3, 4, 3, 4, 6, 6, 4, 7, 5, 6, 9, 8, 9, 10, 9, 9, 9, 15, 9, 15, 12, 11, 15, 13, 12, 20, 18, 16, 15, 21, 17, 21, 18, 20, 21, 25, 20, 22, 23, 25, 24, 27, 22, 29, 26, 28, 31, 34, 26, 35, 32, 26, 33, 35, 30, 41, 33, 36, 34, 42, 35 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

COMMENTS

It is easy to see that a < e < a + b and e^2 + f^2 = 2(a^2 + b^2).

LINKS

Reiner Moewald, Table of n, a(n) for n = 1..200

CROSSREFS

Cf. A224932, A224933.

Sequence in context: A029202 A173894 A285870 * A029195 A242745 A285578

Adjacent sequences:  A224928 A224929 A224930 * A224932 A224933 A224934

KEYWORD

nonn

AUTHOR

Reiner Moewald, Apr 20 2013

STATUS

approved

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Last modified July 16 00:57 EDT 2019. Contains 325061 sequences. (Running on oeis4.)