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A243072 Second order Bulgarian solitaire operation on partition list A112798: a(1) = 1, a(n) = A000040(A001222(n)) * A242424(A064989(n)). 7
1, 2, 4, 3, 8, 6, 12, 5, 9, 12, 20, 10, 28, 18, 18, 7, 44, 15, 52, 20, 27, 30, 68, 14, 36, 42, 25, 30, 76, 30, 92, 11, 45, 66, 54, 21, 116, 78, 63, 28, 124, 45, 148, 50, 50, 102, 164, 22, 81, 60, 99, 70, 172, 35, 90, 42, 117, 114, 188, 42, 212, 138, 75, 13, 126 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The usual Bulgarian Solitaire operation (the "first order" version, cf. A242424) applied to an unordered integer partition means: subtract one from each part, and add a new part as large as there were parts in the old partition.

The "Second Order Bulgarian Solitaire" operation means that after subtracting one from each part of the old partition (and discarding the parts that diminished to zero), we apply the (first order) Bulgarian operation to the remaining partition before adding a new part as large as there were parts in the original partition.

In this context, where the parts of partitions are encoded with the indices of primes in the prime factorization of n (as in A112798), A064989(n) gives the remaining partition after one has been subtracted from each part; A242424 applies the first order Bulgarian operation to it; and multiplying with A000040(A001222(n)) adds a part as large as there originally were parts.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..8192

FORMULA

a(1) = 1, a(n) = A000040(A001222(n)) * A242424(A064989(n)) = A105560(n) * A242424(A064989(n)).

a(n) = A241909(A243052(A241909(n))).

PROG

(Scheme, with Antti Karttunen's IntSeq-library)

(definec (A243072 n) (if (<= n 1) n (* (A000040 (A001222 n)) (A242424 (A064989 n)))))

CROSSREFS

Row 2 of A243070. Differs from A122111 for the first time at n=7.

Cf. A242424, A243073, A112798, A105560, A000040, A001222, A064989, A243052, A241909.

Sequence in context: A271863 A253563 A294044 * A243346 A295029 A329605

Adjacent sequences:  A243069 A243070 A243071 * A243073 A243074 A243075

KEYWORD

nonn

AUTHOR

Antti Karttunen, May 29 2014

STATUS

approved

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Last modified August 8 05:50 EDT 2020. Contains 336290 sequences. (Running on oeis4.)