1,3

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

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

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

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

nonn

Thomas Kerscher, Sep 06 2015

approved