Question 1012848
Natural evens including zero.
{{{A[e]=(0+2+4+6+8+10+12+14+16+18)/10=9}}}
Natural evens excluding zero.
{{{A[e]=(2+4+6+8+10+12+14+16+18)/9=10}}}
Natural odds.
{{{A[o]=(1+3+5+7+9+11+13+15+17+19)/10=10}}}