The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A005917

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A005917

Rhombic dodecahedral numbers: a(n) = n^4 - (n - 1)^4.
(history; published version)

#214 by N. J. A. Sloane at Mon Jan 22 06:01:35 EST 2024

STATUS

proposed

approved

#213 by Robert C. Lyons at Sun Jan 21 15:35:25 EST 2024

STATUS

editing

proposed

Discussion

Mon Jan 22

01:03

Michel Marcus: should be in A212133

06:01

N. J. A. Sloane: you should add a similar comment to A212133

#212 by Robert C. Lyons at Sun Jan 21 15:35:19 EST 2024

COMMENTS

(a(n) + 1) / 2 = A212133(n) is the number of cells in the nth n-th rhombic-dodecahedral polycube. - George Sicherman, Jan 21 2024

STATUS

proposed

editing

#211 by Andrew Howroyd at Sun Jan 21 15:20:49 EST 2024

STATUS

editing

proposed

#210 by Andrew Howroyd at Sun Jan 21 15:19:33 EST 2024

COMMENTS

For n>=1, [(a(n) + 1] ) / 2 = A212133(n) is the number of cells in the nth rhombic-dodecahedral polycube. - George Sicherman, Jan 21 2024

Discussion

Sun Jan 21

15:20

Andrew Howroyd: Since (a(n) + 1) / 2 = A212133(n) the question will be why here?

#209 by Andrew Howroyd at Sun Jan 21 15:15:52 EST 2024

COMMENTS

For n>=1, [a(n) + 1] / 2 is the number of cells in the nth rhombic-dodecahedral polycube. _- _George Sicherman_, Jan 21 2024

EXTENSIONS

Added a comment about rhombic-dodecahedral polycubes.

STATUS

proposed

editing

Discussion

Sun Jan 21

15:18

Alois P. Heinz: comment does not belong here ... terms are in A212133 ...

#208 by George Sicherman at Sun Jan 21 15:06:00 EST 2024

STATUS

editing

proposed

#207 by George Sicherman at Sun Jan 21 15:05:41 EST 2024

COMMENTS

For n>=1, [a(n) + 1] / 2 is the number of cells in the nth rhombic-dodecahedral polycube. George Sicherman, Jan 21 2024

EXTENSIONS

Added a comment about rhombic-dodecahedral polycubes.

STATUS

approved

editing

#206 by Harvey P. Dale at Fri Aug 11 11:33:15 EDT 2023

STATUS

editing

approved

#205 by Harvey P. Dale at Fri Aug 11 11:33:10 EDT 2023

MATHEMATICA

Differences[Range[0, 40]^4] (* Harvey P. Dale, Aug 11 2023 *)

STATUS

approved

editing