A120726 Prime sum of cubes build up triangular array.

2, 3, 7, 5, 9, 41, 7, 11, 43, 11, 15, 47, 155, 13, 17, 49, 157, 17, 21, 53, 161, 417, 19, 23, 55, 163, 419, 23, 27, 59, 167, 423, 29, 33, 65, 173, 429, 31, 35, 67, 175, 431, 931, 37, 41, 73, 181, 437, 937, 41, 45, 77, 185, 441, 941, 1805, 43, 47, 79, 187, 443

Offset

1,1

Links

Table of n, a(n) for n=1..61.

Formula

a(n,m) = prime(m) + 4 * Sum_{i=1..n} i^3.

Example

Array begins:
  2
  3, 7
  5, 9, 41
  7, 11, 43
  11, 15, 47, 155
  13, 17, 49, 157
  17, 21, 53, 161, 417
  19, 23, 55, 163, 419
  23, 27, 59, 167, 423
  29, 33, 65, 173, 429
  ...

Mathematica

t[n_, m_] = Prime[m] + 4*Sum[i^3, {i, 1, n}]; Table[Table[t[n, m], {n, 0, PrimePi[m]}], {m, 1, 10}] // Flatten

Crossrefs

Cf. A120725.

Sequence in context: A069786 A128804 A223702 * A060203 A131880 A045790

Adjacent sequences: A120723 A120724 A120725 * A120727 A120728 A120729

Keyword

nonn,tabf

Author

Roger L. Bagula, Aug 18 2006

Extensions

More terms from Amiram Eldar, Jun 04 2025

Status

approved