A177882 Trisection of A001317.

1, 15, 85, 771, 4369, 65535, 327685, 3342387, 16843009, 252645135, 1431655765, 12884901891, 73014444049, 1095216660735, 5519032976645, 56294136361779, 281479271743489, 4222189076152335, 23925738098196565

Offset: 0

Author

Vladimir Shevelev, Dec 14 2010

Keywords

• nonn

Comments

For n>=1, all terms are in A001969.

Or rows of triangle A008287 mod 2 converted to decimal.

Links

• Gheorghe Coserea, Table of n, a(n) for n = 0..200

Crossrefs

Cf. A001317, A001969, A005190, A007318, A008287.

Programs

Mathematica

f[n_] := BitXor[n, BitShiftLeft[n, 1]]; Table[Nest[f, 1, x], {x, 0, 54, 3}]

PARI

a(n) = subst(lift(Pol(Mod([1, 1, 1, 1], 2), 'x)^n), 'x, 2);
vector(19, n, a(n-1))  \\ Gheorghe Coserea, Jun 12 2016

Python

def A177882(n): return sum((bool(~(3*n)&3*n-k)^1)<Chai Wah Wu, May 02 2023

Formula

a(n) = A001317(3*n).

Extensions

Definition rewritten by N. J. A. Sloane, Jan 01 2011