A334130 Numbers that can be written as a product of distinct triangular numbers.
0, 1, 3, 6, 10, 15, 18, 21, 28, 30, 36, 45, 55, 60, 63, 66, 78, 84, 90, 91, 105, 108, 120, 126, 135, 136, 150, 153, 165, 168, 171, 180, 190, 198, 210, 216, 231, 234, 253, 270, 273, 276, 280, 300, 315, 325, 330, 351, 360, 378, 396, 406, 408, 420, 435, 450
Offset: 1
Keywords
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
- Eric Weisstein's World of Mathematics, Triangular Number
- Index to sequences related to polygonal numbers
Programs
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Maple
N:= 1000: # for all terms <= N S:= {0,1}: for i from 2 do t:= i*(i+1)/2; if t > N then break fi; S:= S union select(`<=`,map(`*`,S,t),N) od: sort(convert(S,list)); # Robert Israel, Apr 21 2020