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A258257 The number of representations of n as a minimal number of triangular numbers, A000217(n) 4
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2, 2, 2, 1, 2, 1, 1, 1, 1, 3, 2, 2, 1, 2, 1, 2, 2, 1, 1, 1, 2, 5, 1, 2, 1, 2, 1, 1, 3, 1, 1, 2, 3, 1, 1, 1, 1, 2, 1, 1, 3, 2, 1, 2, 4, 2, 3, 1, 1, 2, 3, 6, 1, 1, 3, 3, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,16

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..10000

EXAMPLE

a(5) = 1 since 5 = 1 + 1 + 3 is the only representation as a minimal number of three triangular numbers.

a(16) = 2 since 16 = 1 + 15 = 6 + 10 has two representations as a minimal number of two triangular numbers.

MATHEMATICA

t[n_] := n (n + 1)/2; a[n_] := Block[{k = 1, t, tt = t /@ Range[ Sqrt[2*n]]}, While[{} == (r = IntegerPartitions[n, {k}, tt]), k++]; Length@r]; Array[a, 100] (* Giovanni Resta, Jun 09 2015 *)

CROSSREFS

Cf. A061336, A180466.

Sequence in context: A030613 A092984 A297382 * A086600 A218450 A025912

Adjacent sequences:  A258254 A258255 A258256 * A258258 A258259 A258260

KEYWORD

nonn

AUTHOR

Martin Renner, May 24 2015

STATUS

approved

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Last modified November 13 23:48 EST 2019. Contains 329106 sequences. (Running on oeis4.)