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A346225
Number of n-step 4-dimensional nonnegative lattice walks starting at the origin and using steps that increment all components or decrement one component by 1.
2
1, 1, 5, 21, 81, 325, 1433, 6473, 28741, 128457, 585837, 2711361, 12591237, 58423305, 272649261, 1281745485, 6054729657, 28656157453, 135772544321, 645415060421, 3078755726041, 14721799860429, 70493732528001, 337920205112261, 1623127315174873, 7811948782194781
OFFSET
0,3
LINKS
FORMULA
a(n) == 1 (mod 4).
MAPLE
b:= proc(n, l) option remember; `if`(n=0, 1, (k-> `if`(n>min(l),
add(`if`(l[i]=0, 0, b(n-1, sort(subsop(i=l[i]-1, l)))),
i=1..k)+b(n-1, map(x-> x+1, l)), (k+1)^n))(nops(l)))
end:
a:= n-> b(n, [0$4]):
seq(a(n), n=0..27);
CROSSREFS
Column k=4 of A335570.
Sequence in context: A273389 A153008 A292878 * A051196 A273454 A094834
KEYWORD
nonn,walk
AUTHOR
Alois P. Heinz, Jul 11 2021
STATUS
approved