The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A008837 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A008837

a(n) = p*(p-1)/2 for p = prime(n).
(history; published version)

#61 by Joerg Arndt at Tue Nov 22 02:35:37 EST 2022

STATUS

reviewed

approved

#60 by Michel Marcus at Tue Nov 22 02:00:06 EST 2022

STATUS

proposed

reviewed

#59 by Amiram Eldar at Tue Nov 22 01:32:05 EST 2022

STATUS

editing

proposed

#58 by Amiram Eldar at Tue Nov 22 01:10:11 EST 2022

CROSSREFS

Cf. A000010, A000040, A072230, A034953, A271780.

#57 by Amiram Eldar at Tue Nov 22 01:09:22 EST 2022

FORMULA

Product_{n>=2} (1 - 1/a(n)) = A271780. - Amiram Eldar, Nov 22 2022

CROSSREFS

Cf. A072230, A034953, A271780.

STATUS

approved

editing

#56 by Charles R Greathouse IV at Thu Sep 08 08:44:36 EDT 2022

PROG

(MAGMAMagma) [ (k-1)*k/2 where k is NthPrime(n): n in [1..44] ]; // Klaus Brockhaus, Nov 18 2008

Discussion

Thu Sep 08

08:44

OEIS Server: https://oeis.org/edit/global/2944

#55 by Alois P. Heinz at Wed Apr 20 14:35:14 EDT 2022

STATUS

editing

approved

#54 by Alois P. Heinz at Wed Apr 20 14:35:01 EDT 2022

MAPLE

a:= n-> (p-> p*(p-1)/2)(ithprime(n)):

seq(a(n), n=1..65); # Alois P. Heinz, Apr 20 2022

#53 by Alois P. Heinz at Wed Apr 20 14:34:31 EDT 2022

DATA

1, 3, 10, 21, 55, 78, 136, 171, 253, 406, 465, 666, 820, 903, 1081, 1378, 1711, 1830, 2211, 2485, 2628, 3081, 3403, 3916, 4656, 5050, 5253, 5671, 5886, 6328, 8001, 8515, 9316, 9591, 11026, 11325, 12246, 13203, 13861, 14878, 15931, 16290, 18145, 18528, 19306

STATUS

approved

editing

#52 by Harvey P. Dale at Wed Oct 02 13:57:48 EDT 2019

STATUS

editing

approved