A307492 Numbers that are both centered square and square pyramidal.

1, 5, 42925, 1026745

Offset: 1

Author

Ilya Gutkovskiy, Apr 10 2019

Keywords

• nonn
• more

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

Crossrefs

Intersection of A000330 and A001844.

Cf. A008844, A039596, A131750, A307491.

Programs

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 *)