A340047 - OEIS

A340047

Numbers that are the sum of a fourth power s and a square t such that 0 < s < t.

5, 10, 17, 26, 37, 41, 50, 52, 65, 80, 82, 97, 101, 116, 122, 137, 145, 160, 170, 181, 185, 197, 202, 212, 225, 226, 241, 250, 257, 272, 277, 290, 305, 306, 325, 337, 340, 362, 370, 377, 401, 405, 416, 442, 457, 481, 485, 500, 522, 530, 545, 565, 577, 580, 592, 610, 617

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..57.

EXAMPLE

26 is in the sequence since 1^4 + 5^2 = 1 + 25 = 26, where 0 < 1 < 25.

MATHEMATICA

Table[If[Sum[(Floor[i^(1/4)] - Floor[(i - 1)^(1/4)]) (Floor[(n - i)^(1/2)] - Floor[(n - i - 1)^(1/2)]), {i, Floor[(n - 1)/2]}] > 0, n, {}], {n, 800}] // Flatten

CROSSREFS

Cf. A010052.

Sequence in context: A229997 A277186 A193053 * A098749 A034676 A076598

Adjacent sequences: A340044 A340045 A340046 * A340048 A340049 A340050

KEYWORD

nonn

AUTHOR

Wesley Ivan Hurt, Dec 26 2020

STATUS

approved