A068222 An auxiliary bit-mask sequence for computing A066425. (The "dirty", unsymmetric one).

1, 3, 27, 6943, 1819024347, 4000076419257964896255, 77372730618755190082837640024229164347468807163, 237146729315719909074685533605289611245100501015339264143038071525981840734161007646995989118658281471

Offset

1,2

Links

Table of n, a(n) for n=1..8.

A. Karttunen, Scheme functions for computing A066425 and related sequences.

Formula

A068222(1)=1, A068222(n) = A068221(n) | (A068222(n-1) >> A068058(n-1)) [where | means bitwise or and >> is binary right shift]

Crossrefs

The corresponding "clean" bit-mask sequence is A068221. This sequence in binary: A068224. The width of these bit-masks is given by A068739. The position of the rightmost zero bit: A068058. The width of central gap of the term a(n), (n>1) is given by A068059(n-1)-1 = 0, 1, 3, 5, 10, 12, ... (i.e. partial sums of A068058).

Sequence in context: A122217 A316368 A068221 * A308384 A055777 A014222

Adjacent sequences: A068219 A068220 A068221 * A068223 A068224 A068225

Keyword

nonn

Author

Antti Karttunen, Feb 26 2002

Status

approved