A374500 Square pyramidal numbers that are products of smaller square pyramidal numbers.

1, 4900, 513590, 333833500, 711410700, 1042716675, 1429018500, 26088481055, 62366724420, 5223660842400, 18289944673000

Offset

1,2

Links

Table of n, a(n) for n=1..11.

Example

1 is a term because it is a square pyramidal number and equals the empty product.
4900 is a term because it is a square pyramidal number and equals the product of the square pyramidal numbers 5, 5, 14, and 14.
513590 is a term because it is a square pyramidal number and equals the product of the square pyramidal numbers 506 and 1015.
Further examples:
       333833500 = 506*650*1015,
       711410700 = 5*385*369564,
      1042716675 = 55*91*208335,
      1429018500 = 285*650*7714,
     26088481055 = 91*8555*33511,
     62366724420 = 30*3311*627874,
   5223660842400 = 140*12529*2978040,
  18289944673000 = 56980*320988850.

Crossrefs

Row n=4 of A374498.

Cf. A000330, A374501, A374502.

Sequence in context: A220059 A339939 A321146 * A107545 A256363 A031568

Adjacent sequences: A374497 A374498 A374499 * A374501 A374502 A374503

Keyword

nonn,more

Author

Pontus von Brömssen, Jul 09 2024

Status

approved