The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A354329 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A354329

Triangular number nearest to the sum of the first n positive triangular numbers.
(history; published version)

#44 by Peter Luschny at Fri Jul 15 13:49:54 EDT 2022

STATUS

reviewed

approved

#43 by Michel Marcus at Fri Jul 15 13:04:33 EDT 2022

STATUS

proposed

reviewed

#42 by Chai Wah Wu at Fri Jul 15 12:53:37 EDT 2022

STATUS

editing

proposed

#41 by Chai Wah Wu at Fri Jul 15 12:53:32 EDT 2022

PROG

(Python)

from math import isqrt

def A354329(n): return (m:=isqrt(n*(n*(n + 3) + 2)//3))*(m+1)>>1 # Chai Wah Wu, Jul 15 2022

STATUS

approved

editing

#40 by Michael De Vlieger at Fri Jul 15 09:55:45 EDT 2022

STATUS

reviewed

approved

#39 by Michel Marcus at Fri Jul 15 09:29:08 EDT 2022

STATUS

proposed

reviewed

Discussion

Fri Jul 15

09:30

Paolo Xausa: It seemed to me it was more pertinent in A354330, but not in here.

#38 by Paolo Xausa at Fri Jul 15 09:22:15 EDT 2022

STATUS

editing

proposed

Discussion

Fri Jul 15

09:29

Michel Marcus: not sure why you removed A224421, but reviewing

#37 by Paolo Xausa at Fri Jul 15 09:22:01 EDT 2022

CROSSREFS

Cf. A000217, A000292, A053616, A229118, A224421, A354330.

STATUS

proposed

editing

#36 by Paolo Xausa at Tue Jul 05 11:06:53 EDT 2022

STATUS

editing

proposed

#35 by Paolo Xausa at Tue Jul 05 11:05:27 EDT 2022

NAME

Triangular number nearest to the sum of the first n+1 positive triangular numbers.

EXAMPLE

a(4) = 21 because the sum of the first 5 4 positive triangular numbers is 0 + 1 + 3 + 6 + 10 = 20, and the nearest triangular number is 21.

STATUS

proposed

editing

Discussion

Tue Jul 05

11:06

Paolo Xausa: Rephrased name and example to match A351830.