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A243112 a(n) is the smallest number that requires at least n adjacent bit swaps in order to pack all the ones to the right. 1
0, 2, 4, 8, 12, 20, 24, 40, 48, 56, 88, 104, 112, 176, 208, 224, 240, 368, 432, 464, 480, 736, 864, 928, 960, 992, 1504, 1760, 1888, 1952, 1984, 3008, 3520, 3776, 3904, 3968, 4032, 6080, 7104, 7616, 7872, 8000, 8064, 12160, 14208, 15232, 15744, 16000, 16128 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n) = i if and only if A055941(i) == n and A055941(j) < n for all j < i.

Indices where records of A055941 occur.

LINKS

Philippe Beaudoin, Table of n, a(n) for n = 0..132

PROG

(PARI) a055941(n) = {my(b=binary(n)); nb = 0; for (i=1, #b-1, if (b[i], nb += sum(j=i+1, #b, !b[j])); ); nb; }

lista(nn) = {vmax = 0; print1(vmax, ", "); for (n=1, nn, vnew = a055941(n); if (vnew > vmax, vmax = vnew; print1(n, ", "); ); ); } \\ Michel Marcus, Aug 29 2014

(Python)

A243112, a = [0], 0

for n in range(1, 2**30):

....s = bin(n)[2:]

....b = sum(s[i:].count('0') for i, d in enumerate(s, start=1) if d == '1')

....if b > a:

........A243112.append(n)

........a = b # Chai Wah Wu, Sep 07 2014

CROSSREFS

Cf. A055941.

Sequence in context: A206350 A127405 A136034 * A230127 A059793 A118029

Adjacent sequences:  A243109 A243110 A243111 * A243113 A243114 A243115

KEYWORD

nonn,base

AUTHOR

Philippe Beaudoin, Aug 20 2014

STATUS

approved

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Last modified July 5 03:37 EDT 2020. Contains 335459 sequences. (Running on oeis4.)