expand as a binomial series
(p^2 + 3h)^4
( a + b ) ^ 4 =
a ^ 4 + 4 a ^ 3 b + 6 a ^ 2 b ^ 2 + 4 a b ^ 3 + b ^ 4
( p ^ 2 + 3 h ) ^ 4 =
( p ^ 2 ) ^ 4 + 4 ( p ^ 2 ) ^ 3 * 3 h + 6 ( p ^ 2 ) ^ 2 * ( 3 h ^ 2 ) +
4 p ^ 2 * ( 3 h ) ^ 3 + ( 3 h ) ^ 4 =
p ^ 8 + 12 p ^ 6 h + 18 p ^ 4 * 3 h ^ 2 + 4 p ^ 2 * 27 h ^ 3 + 81 h ^ 4 =
p ^ 8 + 12 p ^ 6 h + 54 p ^ 4 h ^ 2 + 108 p ^ 2 h ^ 3 + 81 h ^ 4 =