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Revision History for A229790

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A229790

Cube roots of difference of consecutive cubes, rounded.
(history; published version)

#21 by Harvey P. Dale at Sat Aug 01 18:08:35 EDT 2020

STATUS

editing

approved

#20 by Harvey P. Dale at Sat Aug 01 18:08:31 EDT 2020

MATHEMATICA

Round[Surd[#, 3]]&/@Differences[Range[0, 70]^3] (* Harvey P. Dale, Aug 01 2020 *)

STATUS

approved

editing

#19 by T. D. Noe at Tue Oct 22 14:50:08 EDT 2013

STATUS

editing

approved

#18 by T. D. Noe at Tue Oct 22 14:49:57 EDT 2013

DATA

1, 2, 3, 3, 4, 4, 5, 6, 6, 6, 7, 7, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 24, 24, 24, 24

OFFSET

1,1

0,2

MATHEMATICA

Table[Round[(3*n^2 + 3*n + 1)^(1/3)], {n, 0, 100}] (* T. D. Noe, Oct 22 2013 *)

STATUS

approved

editing

#17 by T. D. Noe at Tue Oct 22 14:47:14 EDT 2013

STATUS

editing

approved

#16 by T. D. Noe at Tue Oct 22 14:46:26 EDT 2013

DATA

2, 3, 3, 4, 4, 5, 6, 6, 6, 7, 7, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26, 26, 26, 26, 27, 27, 27, 27, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 30, 30, 30, 30, 31, 31, 31, 31, 31, 32, 32, 32

STATUS

proposed

editing

Discussion

Tue Oct 22

14:47

T. D. Noe: We like about 260 characters in the Data section. That's three lines after is is approved.

#15 by Charles R Greathouse IV at Tue Oct 22 09:33:10 EDT 2013

STATUS

editing

proposed

#14 by Charles R Greathouse IV at Tue Oct 22 09:33:04 EDT 2013

NAME

cube Cube roots of difference of consecutive cubes , rounded to whole number.

COMMENTS

3x^2+3x+1 is the difference of two adjacent cubes, taking the cube root and rounding to a whole number yields an element of the series. 3 cubes is 27, inserting 3 into the formulat =s 37, 37 plus 27 is 64 the next cube after 27; the cube root of 37 is 3.33222etc rounded to 3 is the element in the series.

EXAMPLE

~3x3n^2+3x3n+1 is the difference of two adjacent cubes, taking the cube root and rounding to a whole number yields an element of the series. 3 cubes is 27, inserting 3 into the formulat formula =s 37, 37 plus 27 is 64 the next cube after 27; the cube root of 37 is 3.33222etc 33222... rounded to 3 is the element in the series.

PROG

(PARI) a(n)=round((3*n*(n+1)+1)^(1/3)) \\ Charles R Greathouse IV, Oct 22 2013

CROSSREFS

Cf. A003215.

KEYWORD

nonn,changed,easy

STATUS

proposed

editing

#13 by Edmund Algeo at Tue Oct 22 07:44:11 EDT 2013

STATUS

editing

proposed

#12 by Michel Marcus at Mon Oct 07 12:39:32 EDT 2013

STATUS

proposed

editing

Discussion

Mon Oct 21

22:28

OEIS Server: This sequence has not been edited or commented on for a week
yet is not proposed for review.  If it is ready for review, please
visit https://oeis.org/draft/A229790 and click the button that reads
"These changes are ready for review by an OEIS Editor."

Thanks.
  - The OEIS Server