A213541 a(n) = n AND n^2, where AND is the bitwise AND operator.

0, 1, 0, 1, 0, 1, 4, 1, 0, 1, 0, 9, 0, 9, 4, 1, 0, 1, 0, 1, 16, 17, 4, 17, 0, 17, 0, 25, 16, 9, 4, 1, 0, 1, 0, 1, 0, 1, 36, 33, 0, 1, 32, 41, 0, 41, 4, 33, 0, 33, 0, 33, 16, 49, 36, 17, 0, 49, 32, 25, 16, 9, 4, 1, 0, 1, 0, 1, 0, 1, 4, 1, 64, 65, 64, 73, 0, 9, 68

Offset: 0

Author

Alex Ratushnyak, Jun 14 2012

Keywords

• nonn
• base
• easy
• less
• look

Comments

The graph of this sequence has the shape of a tilted Sierpinski triangle. - WG Zeist, Jan 15 2019

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..8192

Crossrefs

Cf. A213370.

Cf. A000290.

Cf. A007745 (OR), A169810 (XOR), A002378.

Programs

Haskell

import Data.Bits ((.&.))
a213541 n = n .&. n ^ 2  -- Reinhard Zumkeller, Apr 25 2013

Mathematica

Table[BitAnd[n, n^2], {n, 0, 63}] (* Alonso del Arte, Jun 19 2012 *)

PARI

a(n) = bitand(n, n^2); \\ Michel Marcus, Jan 15 2019

Python

print([n*n & n for n in range(99)])

Formula

a(2^k + x) = a(x) + (x^2 AND 2^k) for 0 <= x < 2^k. - David Radcliffe, May 06 2023