OFFSET
0,3
COMMENTS
XOR the binary representations of n and n^2.
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 0..10000
EXAMPLE
a(5) = 28:
..101 <- 5
11001 <- 25
----- <- XOR
11100 -> 28
MAPLE
f:=proc(n) local i, t0, t1, t2, ts, tl, n1, n2;
t1:=convert(n, base, 2); t2:=convert(n^2, base, 2); n1:=nops(t1); n2:=nops(t2);
if n1 < n2 then ts:= t1; tl:=t2; else ts:=t2; tl:=t1; fi;
t0:=[]; for i from 1 to nops(ts) do t0:=[op(t0), (ts[i] + tl[i]) mod 2 ]; od:
for i from nops(ts)+1 to nops(tl) do t0:=[op(t0), tl[i]]; od:
add(2^(i-1)*t0[i], i=1..nops(t0)); end;
# second Maple program:
a:= n-> Bits[Xor](n, n^2):
seq(a(n), n=0..100); # Alois P. Heinz, Mar 29 2018
MATHEMATICA
a[n_]:=BitXor[n, n^2]; Array[a, 60, 0] (* Robert G. Wilson v, Jun 09 2010 *)
PROG
(Haskell)
import Data.Bits (xor)
a169810 n = n ^ 2 `xor` n :: Integer
-- Reinhard Zumkeller, Dec 27 2012
(PARI) A169810(n)=bitxor(n^2, n) \\ M. F. Hasler, May 07 2023
(Python) A169810=lambda n:n**2^n # M. F. Hasler, May 07 2023
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, May 28 2010
STATUS
approved