The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A126587 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A126587

a(n) is the number of integer lattice points inside the right triangle with legs 3n and 4n (and hypotenuse 5n).
(history; published version)

#51 by Michael De Vlieger at Thu Apr 18 17:56:50 EDT 2024

STATUS

reviewed

approved

#50 by Stefano Spezia at Thu Apr 18 15:21:33 EDT 2024

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proposed

reviewed

#49 by Michel Marcus at Wed Apr 17 11:04:14 EDT 2024

STATUS

editing

proposed

#48 by Michel Marcus at Wed Apr 17 11:04:11 EDT 2024

CROSSREFS

Cf. A000326, A186424, A193832.

STATUS

proposed

editing

#47 by Charlie Marion at Wed Apr 17 11:01:50 EDT 2024

STATUS

editing

proposed

#46 by Charlie Marion at Wed Apr 17 11:01:37 EDT 2024

FORMULA

a(n) = (A000326(2n-1) + A000326(2n))/2. - Charlie Marion, Apr 17 2024

STATUS

approved

editing

#45 by Hugo Pfoertner at Mon Feb 12 06:01:38 EST 2024

STATUS

reviewed

approved

#44 by Joerg Arndt at Mon Feb 12 02:29:30 EST 2024

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proposed

reviewed

#43 by Michel Marcus at Mon Feb 12 02:02:16 EST 2024

STATUS

editing

proposed

#42 by Michel Marcus at Mon Feb 12 02:02:12 EST 2024

FORMULA

By Pick's theorem, a(n) = 6*n^2 - 4*n + 1. - _Nick Hobson (nickh(AT)qbyte.org), _, Mar 13 2007

STATUS

approved

editing