# Formula for oeis A057537

I'm searching for a formula to create http://oeis.org/A057537.

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– deoxygerbe Feb 17 '11 at 12:36
It's on OEIS, in the Maple section. – Peter Taylor Feb 17 '11 at 13:05

I would use a recursion. With [the coins and notes] $c(1)$, $c(2)$, $c(3)$,... $c(m)$ in order, smallest first, I would start with $$b(i,j) = 0 \textrm{ for } j<0 \textrm{ or } i<0$$ $$b(i,0) = 1$$ $$b(0,j) = 0 \textrm{ for } j>0$$ $$b(i,j) = b(i-1,j)+b(i,j-c(j)) \textrm{ for } i,j>0$$ then $b(i,j)$ is the number of ways of making $i$ where the largest part is no bigger than $c(j)$.
So A057537($n$) and similar sequences are simply $b(n,m)$. If the $c(j)$ represent a very large or infinite collection, then you only need to take $m$ large enough, i.e. so $c(m+1)$ is greater than $n$.