OFFSET
3,1
FORMULA
a(n) = (n^12 - 15*n^10 + 55*n^8 + 75*n^6)/720 + O(n^4).
CROSSREFS
KEYWORD
nonn
AUTHOR
Heinrich Ludwig, May 09 2014
EXTENSIONS
a(12)-a(14) from Heinrich Ludwig, Dec 01 2016
a(15)-a(30) from Max Alekseyev, Feb 19 2024
STATUS
approved