1,1

The sum of two consecutive terms of A175428 is always a perfect cube.

Rémy Sigrist, Table of n, a(n) for n = 1..10000

a(n)^3 = A175428(n) + A175428(n+1).

for n = 6:

- A175428(6) + A175428(7) = 135 + 208 = 343 = 7^3,

- hence a(6) = 7.

(PARI) p=1; s=0; for (n=1, 87, s+=2^p; for (v=1, oo, if (!bittest(s, v) && ispower(p+v, 3, &q), print1 (q ", "); p=v; break)))

Cf. A175428.

Sequence in context: A038389 A058223 A245355 * A331305 A279313 A063265

Adjacent sequences: A307782 A307783 A307784 * A307786 A307787 A307788

nonn

Rémy Sigrist, Apr 28 2019

approved