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A261929 a(n) is the number of different pairs (p,q) mod n not of the form (x*y,x+y) mod n for any (x,y). 1
0, 1, 3, 8, 10, 18, 21, 36, 45, 55, 55, 96, 78, 112, 135, 160, 136, 216, 171, 280, 273, 286, 253, 408, 350, 403, 432, 560, 406, 630, 465, 656, 693, 697, 805, 1008, 666, 874, 975, 1180, 820, 1260, 903, 1408, 1485, 1288, 1081, 1728, 1323, 1675, 1683, 1976, 1378, 2025, 2035, 2352, 2109, 2059, 1711, 2880, 1830, 2356 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..62.

FORMULA

a(n) = n^2 - A261928(n).

EXAMPLE

a(2) = 1 because only the pair (1,1) mod 2 doesn't exist as result from any (x*y,x+y) mod 2.

CROSSREFS

Cf. A261928 (number of pairs that have such a form).

Sequence in context: A341939 A244353 A143144 * A020488 A064435 A079541

Adjacent sequences:  A261926 A261927 A261928 * A261930 A261931 A261932

KEYWORD

nonn

AUTHOR

Thomas Kerscher, Sep 06 2015

STATUS

approved

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Last modified June 25 04:09 EDT 2021. Contains 345452 sequences. (Running on oeis4.)