OFFSET
0,7
COMMENTS
If a(n) is arranged in a table with row lengths 5, then the first column is the transpose of the first row, followed the transpose of the second row, followed by the transpose of the third row, and so on. The remainder of each row (except the first) is an arithmetic progression whose start and step size equals the first entry of the row.
a(n) = O(n).
limsup_n a(n) = +oo.
EXAMPLE
a(10) = a(2) * 1 = 1.
a(13) = a(2) * 4 = 4.
PROG
(Python)
def a(n):
if n < 5:
return 1
q, r = divmod(n, 5)
return a(q) * (r + 1)
(PARI) a(n) = if (n < 5, 1, a(n\5)*(n % 5 + 1)); \\ Michel Marcus, Nov 26 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert Dougherty-Bliss, Nov 25 2020
STATUS
approved