A007745 a(n) = n OR n^2 (applied to binary expansions).

1, 6, 11, 20, 29, 38, 55, 72, 89, 110, 123, 156, 173, 206, 239, 272, 305, 342, 379, 404, 445, 502, 535, 600, 633, 702, 731, 796, 861, 926, 991, 1056, 1121, 1190, 1259, 1332, 1405, 1446, 1527, 1640, 1721, 1774, 1851, 1980, 2029, 2158, 2223, 2352, 2417, 2550

Offset: 1

Author

J. P. Mocquard and D. Bouchon (BOUCHON(AT)zeus.univ-poitiers.fr)

Keywords

• base
• nonn
• easy

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A169810 (XOR), A213541 (AND), A002378.

Programs

Haskell

import Data.Bits ((.|.))
a007745 n = n .|. (n ^ 2)  -- Reinhard Zumkeller, Apr 28 2014

Magma

[BitwiseOr(n,n^2): n in [1..50]]; // Bruno Berselli, Mar 30 2018

Maple

a:= n-> Bits[Or](n, n^2):
seq(a(n), n=1..100);  # Alois P. Heinz, Mar 29 2018

Mathematica

(* program should not be used to extend this sequence *)
d = 15; Mb = Array[ 2^(d - #)&, d ]; Map[ Plus@@(Mb*#)&, Array[ IntegerDigits[ #, 2, d ] + IntegerDigits[ #^2, 2, d ]&, 180 ]/. (2->1) ] (* Mocquard and Bouchon *)
Table[BitOr[n, n^2], {n, 100}] (* Vladimir Joseph Stephan Orlovsky, Jul 19 2011 *)

PARI

a(n) = bitor(n, n^2); \\ Michel Marcus, Mar 30 2018