A329418 Lazy caterer's numbers (A000124) that are also cake numbers (A000125).

1, 2, 4, 232, 15226

Offset: 1

Author

Amiram Eldar, Nov 29 2019

Keywords

• nonn
• more

Comments

a(6) > 10^36, if it exists. - Bert Dobbelaere, Jan 18 2020

Examples

			The indices i and j such that a(n) = A000124(i) = A000125(j):
  n   a(n)    i    j
  1      1    0    0
  2      2    1    1
  3      4    2    2
  4    232   21   11
  5  15226  174   45
		

Links

• Wikipedia, Cake number.
• Wikipedia, Lazy caterer's sequence.

Crossrefs

Cf. A000124, A000125.

Programs

Mathematica

lazyCatererQ[n_] := IntegerQ @ Sqrt[8*n - 7]; cake[n_] := Binomial[n, 3] + n; Select[Table[cake[n], {n, 0, 100}], lazyCatererQ]