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A366461 a(n) = number of partitions of n that have the maximum number of neighbors; see Comments. 1

%I #11 Oct 24 2023 15:42:49

%S 1,2,1,2,1,1,2,1,6,1,2,1,6,2,1,2,1,6,2,8,1,2,1,6,2,8,1,1,2,1,6,2,8,1,

%T 6,1,2,1,6,2,8,1,6,22,1,2,1,6,2,8,1,6,22,2,1,2,1,6,2,8,1,6,22,2,8,1,2,

%U 1,6,2,8,1,6,22,2,8,30,1,2,1,6,2,8,1,6,22

%N a(n) = number of partitions of n that have the maximum number of neighbors; see Comments.

%C Partitions p and q of n are neighbors if d(p,q) = 2, where d is the distance function in A366156.

%e Refer to the Example in A366429 to see that a(5) = 1.

%t c[n_] := PartitionsP[n];

%t q[n_, k_] := q[n, k] = IntegerPartitions[n][[k]];

%t r[n_, k_] := r[n, k] = Join[q[n, k], ConstantArray[0, n - Length[q[n, k]]]];

%t d[u_, v_] := d[u, v] = Total[Abs[u - v]];

%t s[n_, k_] := s[n, k] = Select[Range[c[n]], d[r[n, k], r[n, #]] == 2 &]

%t t[n_] := t[n] = Table[s[n, k], {k, 1, c[n]}]

%t a[n_] := Max[Map[Length, t[n]]]

%t b[n_] := b[n] = Select[t[n], Length[#] == a[n] &]

%t e[n_] := Length[b[n]]

%t Table[e[n], {n, 1, 24}]

%Y Cf. A000041, A366156, A366429.

%K nonn

%O 1,2

%A _Clark Kimberling_, Oct 12 2023

%E More terms from _Pontus von Brömssen_, Oct 24 2023

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Last modified September 18 14:58 EDT 2024. Contains 376000 sequences. (Running on oeis4.)