A117798 Icosagonal numbers divisible by 20.

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

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

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

Cf. A008602, A051872.

Sequence in context: A041760 A250550 A292417 * A006424 A291112 A362168

Adjacent sequences: A117795 A117796 A117797 * A117799 A117800 A117801

Keyword

easy,nonn

Author

Luc Stevens (lms022(AT)yahoo.com), Apr 29 2006

Status

approved