1,5

Table of n, a(n) for n=1..74.

a(n) = n - 1 - A061357(n) - A291564(n).

(PARI) a(n)=my(s); for(c=1, n-1, s+=(bigomega(n-c)-1)*(bigomega(n+c)-1)!=0); s

Cf. A061357, A291564.

Sequence in context: A008681 A097242 A183202 * A161308 A161242 A161027

Adjacent sequences: A306875 A306876 A306877 * A306879 A306880 A306881

nonn

Gionata Neri, Mar 14 2019

approved