The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A352996 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A352996

a(n) = n*(n+1)/2 mod (sum (with multiplicity) of prime factors of n).
(history; published version)

#21 by Michael De Vlieger at Sun Apr 24 17:21:45 EDT 2022

STATUS

reviewed

approved

#20 by Michel Marcus at Sun Apr 24 14:31:25 EDT 2022

STATUS

proposed

reviewed

#19 by Michael S. Branicky at Sun Apr 24 13:29:27 EDT 2022

STATUS

editing

proposed

#18 by Michael S. Branicky at Sun Apr 24 13:29:25 EDT 2022

PROG

(Python)

from sympy import factorint

def a(n): return (n*(n+1)//2)%sum(p*e for p, e in factorint(n).items())

print([a(n) for n in range(2, 98)]) # Michael S. Branicky, Apr 24 2022

STATUS

approved

editing

#17 by N. J. A. Sloane at Wed Apr 20 00:08:13 EDT 2022

STATUS

proposed

approved

#16 by Robert Israel at Tue Apr 19 23:13:28 EDT 2022

STATUS

editing

proposed

#15 by Robert Israel at Tue Apr 19 23:08:28 EDT 2022

LINKS

Robert Israel, <a href="/A352996/b352996.txt">Table of n, a(n) for n = 2..10000</a>

STATUS

approved

editing

#14 by N. J. A. Sloane at Mon Apr 18 22:25:33 EDT 2022

STATUS

proposed

approved

#13 by Jon E. Schoenfield at Fri Apr 15 06:39:29 EDT 2022

STATUS

editing

proposed

#12 by Jon E. Schoenfield at Fri Apr 15 06:39:12 EDT 2022

NAME

a(n) = n*(n+1)/2 mod the (sum (with multiplicity) of prime factors of n).

Discussion

Fri Apr 15

06:39

Jon E. Schoenfield: Is this okay?