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A130898
Number of partitions of n into "number of partitions of n into partition numbers" numbers.
3
1, 2, 3, 5, 6, 10, 12, 18, 22, 30, 37, 50, 59, 78, 93, 118, 140, 176, 206, 255, 297, 362, 421, 507, 585, 699, 803, 949, 1088, 1276, 1455, 1696, 1927, 2230, 2527, 2909, 3284, 3761, 4233, 4825, 5416, 6146, 6879, 7778, 8682, 9778, 10892, 12226, 13582, 15200
OFFSET
1,2
COMMENTS
The "partition transformation" of sequence A can be defined as the number of partitions of n into elements of sequence A. This is the partition transformation composed with itself three times on the positive integers.
a(6) = 10 because there are 10 partitions of 6 whose parts are 1,2,3,4,6 which are terms of sequence A007279, which is the number of partitions of n into partition numbers.
LINKS
EXAMPLE
a(6) = 12 because there are 12 partitions of 6 whose parts are 1,2,3,4,6 which are terms of sequence A007279, which is the number of partitions of n into partition numbers.
MAPLE
pp:= proc(p) local b;
b:= proc(n, i)
if n<0 then 0
elif n=0 then 1
elif i<1 then 0
else b(n, i):= b(n, i-1) +b(n-p(i), i)
fi
end;
n-> b(n, n)
end:
a:= (pp@@3)(n->n):
seq(a(n), n=1..100); # Alois P. Heinz, Sep 13 2011
MATHEMATICA
pp[p_] := Module[{b}, b[n_, i_] := Which[n<0, 0, n==0, 1, i<1, 0, True, b[n, i] = b[n, i-1] + b[n-p[i], i]]; b[#, #]&]; a = Nest[pp, Identity, 3]; Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Oct 26 2015, after Alois P. Heinz *)
CROSSREFS
Cf. A000027, A000041, A007279, A130899, A130900 which are m-fold self-compositions of the "partition transformation" on the counting numbers, for m=0, 1, 2, 4, 5.
Sequence in context: A115029 A241443 A023025 * A199016 A088314 A304405
KEYWORD
nonn
AUTHOR
Graeme McRae, Jun 07 2007
STATUS
approved