A307492 Numbers that are both centered square and square pyramidal.

1, 5, 42925, 1026745

Offset

1,2

Comments

If it exists, a(5) > 10^29. - Bert Dobbelaere, Apr 12 2019

Links

Table of n, a(n) for n=1..4.

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.

Cf. A008844, A039596, A131750, A307491.

Sequence in context: A347934 A228547 A193148 * A355959 A165711 A167369

Adjacent sequences: A307489 A307490 A307491 * A307493 A307494 A307495

Keyword

nonn,more

Author

Ilya Gutkovskiy, Apr 10 2019

Status

approved