A374371 Least n-gonal number that can be written as a product of two or more smaller n-gonal numbers, or 0 if no such number exists.

4, 36, 16, 10045, 2850, 6426, 1408, 265926, 69300, 79135, 9504, 195615, 145236, 126630, 42120, 81356859, 9410205, 165550, 1379840, 11340, 3009069, 8321351148, 316200, 47555937, 218338146, 9042726, 822528, 12300400, 300186051, 46955700, 766737400, 206898615

Offset

2,1

Links

Table of n, a(n) for n=2..33.

Example

For 2 <= n <= 33, the n-gonal number a(n) can be written as a product of smaller n-gonal numbers in the following ways:
   n |          a(n)
  ---+---------------------------
   2 |          4 = 2*2
   3 |         36 = 6*6
   4 |         16 = 4*4
   5 |      10045 = 35*287
   6 |       2850 = 15*190
   7 |       6426 = 34*189
   8 |       1408 = 8*176
   9 |     265926 = 46*5781
  10 |      69300 = 10*6930
  11 |      79135 = 95*833
  12 |       9504 = 33*288
  13 |     195615 = 115*1701
  14 |     145236 = 14*10374
  15 |     126630 = 15*42*201
  16 |      42120 = 45*936
  17 |   81356859 = 549*148191
  18 |    9410205 = 343*27435
  19 |     165550 = 175*946
  20 |    1379840 = 20*68992
  21 |      11340 = 21*540
  22 |    3009069 = 427*7047
  23 | 8321351148 = 23*66*5481786
  24 |     316200 = 136*2325
  25 |   47555937 = 351*135487
  26 |  218338146 = 26*8397621
  27 |    9042726 = 154*58719
  28 |     822528 = 28*29376
  29 |   12300400 = 764*16100
  30 |  300186051 = 13051*23001
  31 |   46955700 = 3060*15345
  32 |  766737400 = 5720*134045
  33 |  206898615 = 12615*16401

Crossrefs

Second column of A374370.

Cf. A057145.

Sequence in context: A366729 A092960 A323515 * A144153 A027644 A174426

Adjacent sequences: A374368 A374369 A374370 * A374372 A374373 A374374

Keyword

nonn

Author

Pontus von Brömssen, Jul 07 2024

Status

approved