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URL: https://oeis.org/A307492

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A307492
Numbers that are both centered square and square pyramidal.
1
1, 5, 42925, 1026745
OFFSET
1,2
COMMENTS
If it exists, a(5) > 10^29. - Bert Dobbelaere, Apr 12 2019
LINKS
Eric Weisstein's World of Mathematics, Centered Square Number
Eric Weisstein's World of Mathematics, Square Pyramidal Number
MATHEMATICA
csQ[n_] := IntegerQ[Sqrt[2*n-1]]; Select[Table[n(n+1)(2n+1)/6, {n, 0, 1000}], csQ] (* Amiram Eldar, Apr 11 2019 *)
CROSSREFS
Intersection of A000330 and A001844.
Sequence in context: A347934 A228547 A193148 * A355959 A165711 A167369
KEYWORD
nonn,more
AUTHOR
Ilya Gutkovskiy, Apr 10 2019
STATUS
approved