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A296150
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Triangle whose n-th row is the integer partition with Heinz number n.
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306
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1, 2, 1, 1, 3, 2, 1, 4, 1, 1, 1, 2, 2, 3, 1, 5, 2, 1, 1, 6, 4, 1, 3, 2, 1, 1, 1, 1, 7, 2, 2, 1, 8, 3, 1, 1, 4, 2, 5, 1, 9, 2, 1, 1, 1, 3, 3, 6, 1, 2, 2, 2, 4, 1, 1, 10, 3, 2, 1, 11, 1, 1, 1, 1, 1, 5, 2, 7, 1, 4, 3, 2, 2, 1, 1, 12, 8, 1, 6, 2, 3, 1, 1, 1, 13, 4
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OFFSET
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1,2
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COMMENTS
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The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
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LINKS
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EXAMPLE
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Sequence of partitions begins: (), (1), (2), (11), (3), (21), (4), (111), (22), (31), (5), (211), (6), (41), (32), (1111), (7), (221).
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MAPLE
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f := n -> op(map(numtheory:-pi, sort(map(`$`@op, ifactors(n)[2]), `>`))):
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MATHEMATICA
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Table[If[n===1, {}, Join@@Cases[FactorInteger[n]//Reverse, {p_, k_}:>Table[PrimePi[p], {k}]]], {n, 50}]
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CROSSREFS
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Cf. A000041, A000720, A001222, A056239, A063834, A112798, A196545, A215366, A289501, A299200, A299201, A299202, A299203.
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KEYWORD
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AUTHOR
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STATUS
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approved
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