login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A227589
Maximum label within a minimal labeling of n identical 4-sided dice yielding the most possible sums.
1
1, 4, 7, 12, 16, 23, 29, 38, 46, 57, 67, 80, 92, 107, 121, 138, 154, 173, 191, 212, 232
OFFSET
0,2
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
EXAMPLE
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.
Sequence in context: A310782 A232424 A005005 * A310783 A310784 A310785
KEYWORD
nonn,more
AUTHOR
Jens Voß, Jul 17 2013
STATUS
approved