A177338 Triangle read by rows: R(n,k)=2^(n-tau(k)) mod n, where tau(.) is the number of divisors of its argument.

0, 0, 1, 1, 2, 2, 0, 0, 0, 2, 1, 3, 3, 4, 3, 2, 4, 4, 2, 4, 4, 1, 4, 4, 2, 4, 1, 4, 0, 0, 0, 0, 0, 0, 0, 0, 4, 2, 2, 1, 2, 5, 2, 5, 1, 2, 6, 6, 8, 6, 4, 6, 4, 8, 4, 1, 6, 6, 3, 6, 7, 6, 7, 3, 7, 6, 8, 4, 4, 8, 4, 4, 4, 4, 8, 4, 4, 4, 1, 7, 7, 10, 7, 5, 7, 5, 10, 5, 7, 11, 7, 2, 8, 8, 4, 8, 2, 8

Offset

1,5

Links

Table of n, a(n) for n=1..98.

Example

Triangle begins in row n=1 with columns 1<=k<=n:
0,
0, 1,
1, 2, 2,
0, 0, 0, 2,
1, 3, 3, 4, 3,
2, 4, 4, 2, 4, 4,

Prog

(PARI) trg(nn) = {for (n= 1, nn, for (k = 1, n, print1(2^(n - numdiv(k)) % n, ", "); ); print(); ); } \\ Michel Marcus, Sep 11 2013

Crossrefs

Cf. A000005, A000079, A062173, A154234, A174875.

Sequence in context: A279479 A343630 A318584 * A024158 A054978 A129438

Adjacent sequences: A177335 A177336 A177337 * A177339 A177340 A177341

Keyword

nonn,tabl

Author

Juri-Stepan Gerasimov, Dec 10 2010

Status

approved