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Revision History for A317652 (Underlined text is an addition; strikethrough text is a deletion.)

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A317652 Number of free pure symmetric multifunctions whose leaves are an integer partition of n.
(history; published version)
#9 by Alois P. Heinz at Tue Aug 28 20:20:43 EDT 2018
STATUS

proposed

approved

#8 by Andrew Howroyd at Tue Aug 28 19:50:29 EDT 2018
STATUS

editing

proposed

#7 by Andrew Howroyd at Tue Aug 28 19:23:41 EDT 2018
DATA

1, 1, 2, 6, 22, 93, 421, 2010, 9926, 50357, 260728, 1372436, 7321982, 39504181, 215168221, 1181540841, 6534058589, 36357935615, 203414689462, 1143589234086, 6457159029573, 36602333187792, 208214459462774, 1188252476400972, 6801133579291811, 39032172166792887

LINKS

Andrew Howroyd, <a href="/A317652/b317652.txt">Table of n, a(n) for n = 0..200</a>

PROG

(PARI) EulerT(v)={Vec(exp(x*Ser(dirmul(v, vector(#v, n, 1/n))))-1, -#v)}

seq(n)={my(v=[]); for(n=1, n, my(t=EulerT(v)); v=concat(v, 1 + sum(k=1, n-1, v[k]*t[n-k]))); concat([1], v)} \\ Andrew Howroyd, Aug 28 2018

KEYWORD

nonn,more

nonn

EXTENSIONS

Terms a(12) and beyond from Andrew Howroyd, Aug 28 2018

STATUS

approved

editing

#6 by Susanna Cuyler at Fri Aug 03 08:16:44 EDT 2018
STATUS

proposed

approved

#5 by Gus Wiseman at Fri Aug 03 05:29:48 EDT 2018
STATUS

editing

proposed

#4 by Gus Wiseman at Fri Aug 03 05:29:21 EDT 2018
EXAMPLE

The a(4) = 22 free pure symmetric multifunctions:

#3 by Gus Wiseman at Fri Aug 03 04:56:52 EDT 2018
CROSSREFS

Cf. A317653, A317654, A317655, A317656, A317658.

#2 by Gus Wiseman at Fri Aug 03 03:56:58 EDT 2018
NAME

allocatedNumber of free pure symmetric multifunctions whose leaves are an integer forpartition Gusof Wisemann.

DATA

1, 1, 2, 6, 22, 93, 421, 2010, 9926, 50357, 260728, 1372436

OFFSET

0,3

COMMENTS

A free pure symmetric multifunction f in EPSM is either (case 1) a positive integer, or (case 2) an expression of the form h[g_1, ..., g_k] where k > 0, h is in EPSM, each of the g_i for i = 1, ..., k is in EPSM, and for i < j we have g_i <= g_j under a canonical total ordering of EPSM, such as the Mathematica ordering of expressions.

EXAMPLE

The a(4) = 22 free pure symmetric multifunctions:

1[1[1[1]]] 1[1[2]] 1[3] 2[2] 4

1[1[1][1]] 1[2[1]] 3[1]

1[1][1[1]] 2[1[1]]

1[1[1]][1] 1[1][2]

1[1][1][1] 1[2][1]

1[1[1,1]] 2[1][1]

1[1,1[1]] 1[1,2]

1[1][1,1] 2[1,1]

1[1,1][1]

1[1,1,1]

MATHEMATICA

sps[{}]:={{}}; sps[set:{i_, ___}]:=Join@@Function[s, Prepend[#, s]&/@sps[Complement[set, s]]]/@Cases[Subsets[set], {i, ___}];

mps[set_]:=Union[Sort[Sort/@(#/.x_Integer:>set[[x]])]&/@sps[Range[Length[set]]]];

exprUsing[m_]:=exprUsing[m]=If[Length[m]==0, {{}}, If[Length[m]==1, {First[m]}, Join@@Cases[Union[Table[PR[m[[s]], m[[Complement[Range[Length[m]], s]]]], {s, Take[Subsets[Range[Length[m]]], {2, -2}]}]], PR[h_, g_]:>Join@@Table[Apply@@@Tuples[{exprUsing[h], Union[Sort/@Tuples[exprUsing/@p]]}], {p, mps[g]}]]]];

Table[Sum[Length[exprUsing[y]], {y, IntegerPartitions[n]}], {n, 0, 6}]

CROSSREFS

Cf. A001003, A052893, A053492, A277996, A279944, A280000.

KEYWORD

allocated

nonn,more

AUTHOR

Gus Wiseman, Aug 03 2018

STATUS

approved

editing

#1 by Gus Wiseman at Fri Aug 03 03:56:58 EDT 2018
NAME

allocated for Gus Wiseman

KEYWORD

allocated

STATUS

approved

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Last modified August 30 00:57 EDT 2024. Contains 375520 sequences. (Running on oeis4.)