A177882 - OEIS

A177882

Trisection of A001317.

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

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

FORMULA

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

MATHEMATICA

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

PROG

(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)<<k for k in range(3*n+1)) # Chai Wah Wu, May 02 2023

CROSSREFS

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

Sequence in context: A064058 A138322 A206170 * A199897 A367228 A309922

Adjacent sequences: A177879 A177880 A177881 * A177883 A177884 A177885

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Dec 14 2010

EXTENSIONS

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

STATUS

approved