OFFSET
1,3
COMMENTS
a(n) is the sum of the larger parts raised to the corresponding smaller parts of the partitions of n into exactly two parts.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..773
FORMULA
a(n) = Sum_{i=1..floor(n/2)} (n-i)^i.
EXAMPLE
a(6) = 48; 6 has exactly 3 partitions into two parts: (5,1),(4,2),(3,3). Raising the larger parts to their corresponding smaller parts and adding the results, we get: 5^1 + 4^2 + 3^3 = 5 + 16 + 27 = 48.
MATHEMATICA
Array[Sum[(# - i)^i, {i, Floor[#/2]}] &, 25] (* Michael De Vlieger, Jan 23 2018 *)
PROG
(PARI) a(n) = sum(k=1, n\2, (n-k)^k); \\ Michel Marcus, Dec 13 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, May 27 2013
STATUS
approved