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A289895 Numbers that are the sum of distinct square pyramidal numbers (A000330). 1
0, 1, 5, 6, 14, 15, 19, 20, 30, 31, 35, 36, 44, 45, 49, 50, 55, 56, 60, 61, 69, 70, 74, 75, 85, 86, 90, 91, 92, 96, 97, 99, 100, 104, 105, 106, 110, 111, 121, 122, 126, 127, 135, 136, 140, 141, 145, 146, 147, 151, 152, 154, 155, 159, 160, 161, 165, 166, 170, 171, 175, 176, 177, 181, 182, 184, 185, 189, 190, 191, 195, 196, 200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

It appears that 1528 is the largest of 306 positive integers not in this sequence.

LINKS

Table of n, a(n) for n=1..73.

Index entries for sequences related to sums of squares

Index to sequences related to pyramidal numbers

FORMULA

Exponents in expansion of Product_{k>=1} (1 + x^(k*(k+1)*(2*k+1)/6)).

EXAMPLE

20 is in the sequence because 20 = 1 + 5 + 14 = 1^2 + 1^2 + 2^2 + 1^2 + 2^2 + 3^2.

MATHEMATICA

max = 200; f[x_] := Product[1 + x^(k (k + 1) (2 k + 1)/6), {k, 1, 10}]; Exponent[#, x] & /@ List @@ Normal[Series[f[x], {x, 0, max}]]

CROSSREFS

Cf. A000330, A003995.

Sequence in context: A314292 A294572 A084381 * A335785 A266304 A308839

Adjacent sequences:  A289892 A289893 A289894 * A289896 A289897 A289898

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Jul 14 2017

STATUS

approved

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Last modified September 19 15:09 EDT 2020. Contains 337178 sequences. (Running on oeis4.)