A153661 Triangle read by rows: R(n,k) = 2^(composite(n)-composite(k)) mod composite(n), 1<=k<=n.

1, 4, 1, 0, 4, 1, 5, 8, 2, 1, 4, 6, 4, 2, 1, 4, 4, 4, 8, 4, 1, 2, 4, 8, 4, 2, 4, 1, 8, 2, 8, 4, 2, 8, 2, 1, 0, 0, 0, 0, 0, 0, 4, 2, 1, 4, 10, 16, 8, 4, 10, 16, 8, 4, 1, 16, 4, 16, 8, 4, 16, 4, 12, 16, 4, 1, 11, 8, 2, 1, 11, 8, 2, 1, 11, 8, 2, 1, 14, 20, 16, 8, 4, 12, 14, 18, 20, 16, 4, 2, 1, 16, 16, 16, 8, 16, 16, 16, 8, 16, 16, 16, 8, 4, 1

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..1035

Example

Triangle begins:
1,
4, 1,
0, 4, 1,
5, 8, 2, 1,
4, 6, 4, 2, 1,
4, 4, 4, 8, 4, 1,

Maple

A153661 := proc(n, k) modp(2^(A002808(n)-A002808(k)), A002808(n)) ; end proc: # R. J. Mathar, Dec 15 2010

Mathematica

Composite[m_] := FixedPoint[m + PrimePi[#] + 1 &, m + PrimePi[m] + 1]; a[n_, k_] := Mod[2^(Composite[n] - Composite[k]), Composite[n]]; Table[a[n, k], {n, 1, 15}, {k, 1, n}]; Flatten[%] (* G. C. Greubel, Aug 24 2016 *)

Crossrefs

Cf. A000079, A002808, A175156.

Sequence in context: A216178 A122899 A223856 * A266392 A021713 A122388

Adjacent sequences: A153658 A153659 A153660 * A153662 A153663 A153664

Keyword

nonn,tabl,easy,less

Author

Juri-Stepan Gerasimov, Dec 12 2010

Extensions

Terms corrected by R. J. Mathar, Dec 15 2010

Status

approved