

A134938


Pentagonal numbers that are the sum of a nonzero pentagonal number and a nonzero square in at least one way.


2



5, 51, 117, 145, 247, 425, 651, 715, 852, 1001, 1247, 1717, 1820, 2147, 2501, 3015, 3151, 4187
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OFFSET

1,1


LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000


MATHEMATICA

Module[{nn=100, pent}, pent=PolygonalNumber[5, Range[nn]]; Select[Flatten[ Outer[ Plus, pent, Range[Sqrt[Max[pent]]]^2]]//Union, IntegerQ[ (1+Sqrt[ 1+24#])/6]&]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 27 2020 *)


CROSSREFS

Sequence in context: A333261 A117710 A064019 * A068540 A208997 A041043
Adjacent sequences: A134935 A134936 A134937 * A134939 A134940 A134941


KEYWORD

nonn


AUTHOR

Jonathan Vos Post, Jan 21 2008


STATUS

approved



