OFFSET
0,3
COMMENTS
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..9395 (rows for n = 0..17 flattened)
EXAMPLE
The binary tree starts with root 0 in row n = 0. In row n = 3, the parent node m = 3 has the first left child since 3 - 3 >= 0.
The tree begins:
row
[n]
[0] 0
\
[1] 1
\
[2] ___3___
/ \
/ \
[3] 0 __6__
\ / \
[4] 4 2 10
\ \ / \
[5] 9 7 5 15
MAPLE
T:= proc(n) option remember; `if`(n=0, 0, map(x->
[`if`(x<n, [][], x-n), x+n][], [T(n-1)])[])
end:
seq(T(n), n=0..10); # Alois P. Heinz, Jan 30 2023
PROG
(Python)
def A360173_rowlist(row_n):
A = [[0]]
for i in range(0, row_n):
A.append([])
for j in range(0, len(A[i])):
x = A[i][j]
if x - i -1 >= 0:
A[i+1].append(x-i-1)
if x + i + 1 >= 0:
A[i+1].append(x+i+1)
return(A)
(PARI) row(n) = { my (r=[0]); for (h=1, n, r=concat(apply(v->if (v-h>=0, [v-h, v+h], [v+h]), r))); return (r) } \\ Rémy Sigrist, Jan 31 2023
CROSSREFS
KEYWORD
AUTHOR
John Tyler Rascoe, Jan 28 2023
STATUS
approved