A066606 a(n) = 2^n mod n^2.

0, 0, 8, 0, 7, 28, 30, 0, 26, 24, 112, 64, 80, 116, 143, 0, 155, 28, 116, 176, 197, 444, 255, 64, 57, 316, 80, 128, 60, 424, 374, 0, 602, 616, 18, 784, 76, 460, 944, 576, 207, 1324, 303, 1600, 782, 1016, 1929, 1792, 2382, 124, 1844, 2512, 1009, 568, 1693, 704

Offset

1,3

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from Harry J. Smith)

Example

a(7) = 30 as 2^7 = 128 = (7^2)*2 + 30.

Maple

a:= n-> 2&^n mod (n^2):
seq(a(n), n=1..100);  # Alois P. Heinz, Jul 04 2017

Mathematica

Table[ Mod[ 2^n, n^2], {n, 1, 60} ]
Table[PowerMod[2, n, n^2], {n, 60}] (* Harvey P. Dale, Dec 08 2015 *)

Prog

(PARI) { for (n=1, 1000, write("b066606.txt", n, " ", 2^n % n^2) ) } \\ Harry J. Smith, Mar 10 2010

Crossrefs

Sequence in context: A262522 A174849 A133741 * A048729 A003131 A010679

Adjacent sequences: A066603 A066604 A066605 * A066607 A066608 A066609

Keyword

easy,nonn

Author

Amarnath Murthy, Dec 22 2001

Extensions

More terms from Floor van Lamoen and Robert G. Wilson v, Dec 23 2001

Status

approved