A365019 Triangular numbers that for some k >= 0 are also the sum of the first k perfect powers.

0, 1, 159284476

Offset

1,3

Links

Table of n, a(n) for n=1..3.

Example

159284476 is a term because 159284476 = 1 + 2 + 3 + 4 + ... + 17848 = 1 + 4 + 8 + 9 + ... + 574564 = 1^2 + 2^2 + 2^3 + 3^2 + ... + 758^2.

Mathematica

Join[{0}, Select[Accumulate[Select[Range[574564], # == 1 || GCD @@ FactorInteger[#][[All, 2]] > 1 &]], IntegerQ[Sqrt[8 # + 1]] &]]

Crossrefs

Cf. A000217, A001597, A066527, A076408, A298270.

Sequence in context: A251489 A205641 A118078 * A151695 A343079 A116643

Adjacent sequences: A365016 A365017 A365018 * A365020 A365021 A365022

Keyword

nonn,bref,hard,more

Author

Ilya Gutkovskiy, Aug 16 2023

Status

approved