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A336433 Number of sequences of n numbers from 1 to n that do not have a subsequence that adds up to n. 1
0, 0, 0, 1, 5, 68, 403, 7257, 61686, 1174434, 13810620, 335547727, 3783688286, 124486381056, 1935430229612, 55798127869680, 1058567311736669, 39819079382937334, 717447490866241055, 32064848897165970340, 666062878027691348450, 28916070816360797805534 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

The sequence is bounded above for odd n by (((n-1)/2)^n)*(2^((n-1)/2)).

Growth appears to be slightly faster than exponential, but irregular, with odd-numbered terms larger than the trend.

LINKS

Christopher L. Reedy, Table of n, a(n) for n = 1..30

Pierre Abbat, Fullproc

Christopher L. Reedy, sequence.py

EXAMPLE

For n=3, the only solution is 2,2,2.

For n=4, the 5 solutions are 3,3,3,3 and the four permutations of 3,3,3,2.

PROG

(C++) See Fullproc link.

(Python) See sequence.py link.

CROSSREFS

Cf. A000312.

Sequence in context: A252794 A328359 A003361 * A099334 A281558 A165396

Adjacent sequences:  A336427 A336428 A336429 * A336434 A336436 A336437

KEYWORD

nonn

AUTHOR

Pierre Abbat, Jul 21 2020

EXTENSIONS

a(19)-a(21) from Christopher L. Reedy, Aug 06 2020

STATUS

approved

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Last modified September 28 08:33 EDT 2020. Contains 337394 sequences. (Running on oeis4.)