Derive a formula for the number of partitions of n into parts that are odd and bigger than 1; e.g. a(12)=5 cases: 3+3+3+3, 5+7, 7+5, 3+9, 9+3.

Verify your formula by evaluating a(14).

(In reply to P is for what? by Jer)

I assume what you mean for the closed formula is the asymptotic formula given in the OEIS:

Set r = 1.3247179572447 and plug into r ^ n / (2 * r + 3).

Indeed if you round the formula to the nearest integer, it seems to work for all n > 4; that is, 4 is the largest n for which if fails.

Posted by Charlie on 2013-01-24 19:36:43