login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A307785 a(n) is the cubic root of A175428(n) + A175428(n+1). 1
2, 3, 4, 5, 6, 7, 6, 3, 4, 5, 6, 7, 6, 3, 4, 5, 6, 7, 6, 3, 4, 5, 6, 7, 6, 3, 4, 5, 6, 7, 6, 3, 4, 5, 6, 7, 6, 3, 4, 5, 6, 7, 8, 7, 4, 5, 6, 5, 2, 3, 4, 5, 6, 7, 6, 2, 3, 4, 5, 6, 7, 8, 9, 8, 5, 4, 5, 6, 7, 8, 7, 5, 6, 7, 6, 4, 5, 6, 7, 8, 9, 10, 9, 6, 5, 6, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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

LINKS

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

FORMULA

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

EXAMPLE

for n = 6:

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

- hence a(6) = 7.

PROG

(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)))

CROSSREFS

Cf. A175428.

Sequence in context: A038389 A058223 A245355 * A279313 A063265 A211011

Adjacent sequences:  A307782 A307783 A307784 * A307786 A307787 A307788

KEYWORD

nonn

AUTHOR

Rémy Sigrist, Apr 28 2019

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 10 12:30 EST 2019. Contains 329895 sequences. (Running on oeis4.)