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A064660 The number of distinct parts in the partition sequence lambda(n) formed by the recurrence lambda(1) = 1 and lambda(n+1) is the sum of lambda(n) and its conjugate. 1
1, 1, 2, 3, 4, 6, 8, 11, 15, 22, 30, 39, 53, 75, 106, 151, 215, 297, 424, 592, 835, 1162, 1618, 2274, 3217, 4556, 6361, 8940, 12560, 17645, 24822, 34812, 48967, 68861, 96939, 136462, 191896, 269976, 379726, 534239, 751829, 1058170, 1489038, 2096243, 2951262 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

lambda(n) is a partition of 2^(n-1).

The largest part of lambda(n) is A000045(n).

The number of parts of lambda(n) is A000045(n+1). Peter J. Taylor, Jul 24 2014

LINKS

Table of n, a(n) for n=1..45.

EXAMPLE

lambda(4) = 3+2+1+1+1 has conjugate partition 5+2+1, so lambda(5) = 5+3+2+2+1+1+1+1 and a(5) = |{5,3,2,1}| = 4.

CROSSREFS

Cf. A000700, A000701, A000045.

Sequence in context: A003411 A034081 A289432 * A321359 A321567 A066806

Adjacent sequences:  A064657 A064658 A064659 * A064661 A064662 A064663

KEYWORD

nonn

AUTHOR

Naohiro Nomoto, Feb 14 2002

EXTENSIONS

More terms, description and example rephrased by Peter J. Taylor, Jul 24 2014

STATUS

approved

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Last modified July 10 13:04 EDT 2020. Contains 335576 sequences. (Running on oeis4.)