OFFSET
1,5
LINKS
Peter Kagey, Table of n, a(n) for n = 1..9987 (first 1000 rows)
FORMULA
T(n,0) = 0 and T(n, A070939(n)) = n.
EXAMPLE
For n = 26 and k = 3, T(26, 3) = 2 because 26 = 11010_2, and looking at only the last three bits gives 010_2 = 2.
Table begins:
n\k| 0 1 2 3 4
---+-----------
1 | 0 1
2 | 0 0 2
3 | 0 1 3
4 | 0 0 0 4
5 | 0 1 1 5
6 | 0 0 2 6
7 | 0 1 3 7
8 | 0 0 0 0 8
9 | 0 1 1 1 9
MATHEMATICA
T[n_, k_] := BitAnd[n, 2^k-1]; Table[T[n, k], {n, 1, 20}, {k, 0, BitLength[n]}] // Flatten (* Amiram Eldar, Aug 09 2019 *)
PROG
(Ruby)
def t(n, k); n & (1 << k) - 1 end
CROSSREFS
KEYWORD
AUTHOR
Peter Kagey, Aug 08 2019
STATUS
approved