A227589 Maximum label within a minimal labeling of n identical 4-sided dice yielding the most possible sums.
1, 4, 7, 12, 16, 23, 29, 38, 46, 57, 67, 80, 92, 107, 121, 138, 154, 173, 191, 212, 232
Offset: 0
Examples
Three tetrahedra labeled (1, 2, 8, 12) yield the 20 possible sums 3, 4, 5, 6, 10, 11, 12, 14, 15, 16, 17, 18, 21, 22, 24, 25, 26, 28, 32, 36. No more sums can be obtained by different labelings, and no labeling with labels < 12 yields 20 possible sums. Therefore a(3) = 12.
Crossrefs
Row n=4 of array A227588.
Formula
Conjecture: a(n) = (n^2 + 3n + 5 - (-1)^n)/2 for n > 1.
Conjecture: a(n) = 2*a(n-1)-2*a(n-3)+a(n-4) for n>5. G.f.: (x^5-x^4-x^2+2*x+1) / ((x-1)^3*(x+1)). - Colin Barker, Aug 01 2013