A061531 Boustrophedon transform of b(0)=1 and otherwise b(n)=mu(n).

1, 2, 2, 1, 3, 10, 37, 173, 865, 4987, 31695, 222088, 1696285, 14039493, 125126705, 1194880848, 12170926545, 131720400008, 1509404188204, 18257416121656, 232460634872927, 3107769796958470, 43526289269263574, 637323017146341113

Offset

0,2

Links

Table of n, a(n) for n=0..23.

Index entries for sequences related to boustrophedon transform

Example

a(5) = 10+mu(4) = (9+1)+0 = (6+3)+1+0 = (2+4)+4+0 = (-1+3)+8+0 = mu(5)+a(4)+8+mu(4).

Prog

(Python)
from itertools import count, islice, accumulate
from sympy import mobius
def A061531_gen(): # generator of terms
    blist, m = tuple(), 1
    for i in count(1):
        yield (blist := tuple(accumulate(reversed(blist), initial=m)))[-1]
        m = mobius(i)
A061531_list = list(islice(A061531_gen(), 20)) # Chai Wah Wu, Jun 11 2022

Crossrefs

mu(n) = A008683(n) = ((-1)^A001221(n))*(0^(A001222(n)-A001221(n))).

Sequence in context: A241186 A258222 A112324 * A368093 A368116 A338435

Adjacent sequences: A061528 A061529 A061530 * A061532 A061533 A061534

Keyword

easy,nonn

Author

Frank Ellermann, Jun 13 2001

Status

approved