A374499 - OEIS

A374499

Least n-gonal pyramidal number that can be written as a product of two or more smaller n-gonal pyramidal numbers, or 0 if no such number exists.

36, 560, 4900, 56448, 4750, 58372180608, 1130220, 6252757280000

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OFFSET

2,1

COMMENTS

a(11) = 4200, a(13) = 5521090680, a(14) = 748980.

LINKS

EXAMPLE

For 2 <= n <= 9, the n-gonal pyramidal number a(n) can be written as a product of smaller n-gonal pyramidal numbers in the following ways:

n | a(n)

--+-------------------------------------

2 | 36 = 6*6

3 | 560 = 4*4*35 = 10*56

4 | 4900 = 5*5*14*14

5 | 56448 = 196*288

6 | 4750 = 50*95

7 | 58372180608 = 196*456*653108

8 | 1130220 = 9*70*1794

9 | 6252757280000 = 10*10*10*80*78159466

CROSSREFS

Second column of A374498.

KEYWORD

nonn,more

AUTHOR

STATUS

approved