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A055402
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Least number represented as the sum of n cubes with greedy algorithm.
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1
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1, 2, 3, 4, 5, 6, 7, 15, 23, 50, 114, 330, 1330, 10591, 215970, 19464802, 16542386125, 409477218238718, 1594640520554911022654, 12254971660196485116306102211582, 8256321288165573196207266557193504883194549246
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = a(n-1) + ceiling(sqrt(a(n-1)/3 + 1/4) - 1/2)^3 for n >= 2.
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EXAMPLE
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a(11) = 114 = 64 + 27 + 8 + 8 + 1 + 1 + 1 + 1 + 1 + 1 + 1.
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PROG
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(PARI)
{default(realprecision, 255); v = []; n = 1;
while(n < 29,
if(n < 8,
a = n, a = v[n-1] + ceil(sqrt(v[n-1]/3 + 1/4) - 1/2)^3);
v = concat(v, a);
write("b055402.txt", n, " ", v[n]); n++)}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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