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A294080 Same-tree Moebius function of the multiorder of integer partitions indexed by Heinz numbers. 4
0, 1, 1, -1, 1, 0, 1, -1, -1, 0, 1, 2, 1, 0, 0, -2, 1, 0, 1, 0, 0, 0, 1, 0, -1, 0, -1, 0, 1, 0, 1, -1, 0, 0, 0, 3, 1, 0, 0, 2, 1, 0, 1, 0, 0, 0, 1, -3, -1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 2, -1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, -2, 0, 1, -4, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,12

COMMENTS

By convention a(1) = 0.

The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

FORMULA

mu(y) = Sum_{g(t)=y} (-1)^d(t), where the sum is over all same-trees (A281145, A294019) whose multiset of leaves is the integer partition y, and d(t) is the number of non-leaf nodes in t.

MATHEMATICA

nn=120;

ptns=Table[If[n===1, {}, Join@@Cases[FactorInteger[n]//Reverse, {p_, k_}:>Table[PrimePi[p], {k}]]], {n, nn}];

tris=Join@@Map[Tuples[IntegerPartitions/@#]&, ptns];

rmu[y_]:=rmu[y]=If[Length[y]===1, 1, -Sum[Times@@rmu/@t, {t, Select[tris, And[Length[#]>1, Sort[Join@@#, Greater]===y, SameQ@@Total/@#]&]}]];

rmu/@ptns

PROG

(PARI)

A056239(n) = { my(f); if(1==n, 0, f=factor(n); sum(i=1, #f~, f[i, 2] * primepi(f[i, 1]))); }

muifbalancedfactorization(v) = if(!#v, 1, my(pw=A056239(v[1]), m=-1); for(i=1, #v, if(A056239(v[i])!=pw, return(0), m *= A294080(v[i]))); (m));

A294080aux(n, m, facs) = if(1==n, muifbalancedfactorization(Vec(facs)), my(s=0, newfacs); fordiv(n, d, if((d>1)&&(d<=m), newfacs = List(facs); listput(newfacs, d); s += A294080aux(n/d, m, newfacs))); (s));

A294080(n) = if(1==n, 0, if(isprime(n), 1, A294080aux(n, n-1, List([]))));

\\ A memoized implementation:

map294080 = Map();

A294080(n) = if(1==n, 0, if(isprime(n), 1, if(mapisdefined(map294080, n), mapget(map294080, n), my(v=A294080aux(n, n-1, List([]))); mapput(map294080, n, v); (v)))); \\ Antti Karttunen, Sep 22 2018

CROSSREFS

Cf. A000041, A056239, A063834, A196545, A273873, A281145, A289501, A294018, A294019, A296150, A299202, A299203.

Sequence in context: A280125 A280586 A112344 * A294019 A123721 A077618

Adjacent sequences:  A294077 A294078 A294079 * A294081 A294082 A294083

KEYWORD

sign

AUTHOR

Gus Wiseman, Feb 07 2018

STATUS

approved

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Last modified July 10 00:05 EDT 2020. Contains 335570 sequences. (Running on oeis4.)