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A117798
Icosagonal numbers divisible by 20.
2
0, 20, 820, 1200, 3440, 4180, 7860, 8960, 14080, 15540, 22100, 23920, 31920, 34100, 43540, 46080, 56960, 59860, 72180, 75440, 89200, 92820, 108020, 112000, 128640, 132980, 151060, 155760, 175280, 180340, 201300, 206720, 229120, 234900, 258740
OFFSET
1,2
COMMENTS
Intersection of A008602 and A051872. - Michel Marcus, Feb 27 2014
LINKS
MATHEMATICA
Select[Table[PolygonalNumber[20, n], {n, 0, 200}], Divisible[#, 20] &] (* Amiram Eldar, Mar 22 2021 *)
PROG
(PARI) isok(n) = ispolygonal(n, 20) && !(n % 20); \\ Michel Marcus, Feb 27 2014
CROSSREFS
Sequence in context: A041760 A250550 A292417 * A006424 A291112 A362168
KEYWORD
easy,nonn
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), Apr 29 2006
STATUS
approved