A055402 Least number represented as the sum of n cubes with greedy algorithm.

1, 2, 3, 4, 5, 6, 7, 15, 23, 50, 114, 330, 1330, 10591, 215970, 19464802, 16542386125, 409477218238718, 1594640520554911022654, 12254971660196485116306102211582, 8256321288165573196207266557193504883194549246

Offset

1,2

Links

Rick L. Shepherd, Table of n, a(n) for n = 1..28

Formula

a(n) = a(n-1) + ceiling(sqrt(a(n-1)/3 + 1/4) - 1/2)^3 for n >= 2.

Example

a(11) = 114 = 64 + 27 + 8 + 8 + 1 + 1 + 1 + 1 + 1 + 1 + 1.

Prog

(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++)}
\\ Rick L. Shepherd, Jan 30 2014

Crossrefs

Cf. A006892, A055401.

Sequence in context: A146028 A263469 A165804 * A274839 A361809 A367933

Adjacent sequences: A055399 A055400 A055401 * A055403 A055404 A055405

Keyword

nonn

Author

Henry Bottomley, May 16 2000

Extensions

More terms from Vladeta Jovovic, Jul 03 2001

Status

approved