The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A271565

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A271565

Number of 8's found in the first differences of a reduced residue system modulo a primorial p#.
(history; published version)

#18 by Joerg Arndt at Tue Nov 14 04:35:44 EST 2023

STATUS

reviewed

approved

#17 by Amiram Eldar at Tue Nov 14 03:58:35 EST 2023

STATUS

proposed

reviewed

#16 by Michel Marcus at Tue Nov 14 00:54:36 EST 2023

STATUS

editing

proposed

#15 by Michel Marcus at Tue Nov 14 00:54:04 EST 2023

LINKS

Steven Brown, <a href="https://arxiv.org/abs/2311.06873">Distance between consecutive elements of the multiplicative group of integers modulo n</a>, arXiv:2311.06873 [math.NT], 2023. See Table 1 p. 25.

STATUS

approved

editing

#14 by N. J. A. Sloane at Mon Apr 11 23:36:27 EDT 2016

STATUS

editing

approved

#13 by N. J. A. Sloane at Mon Apr 11 23:36:10 EDT 2016

FORMULA

a(n) = product(p-2) - 2*product(p-3) + product(p-4), when where p runs over through the primes greater than > 3 and until p <= prime(n).

STATUS

proposed

editing

Discussion

Mon Apr 11

23:36

N. J. A. Sloane: I further clarified the formula

#12 by Michel Marcus at Mon Apr 11 15:48:35 EDT 2016

STATUS

editing

proposed

#11 by Michel Marcus at Mon Apr 11 15:46:09 EDT 2016

FORMULA

a(n) = product(p-2) - 2*product(p-3) + product(p-4), when p runs over the primes greater than 3 and until p = prime(n).

STATUS

proposed

editing

Discussion

Mon Apr 11

15:46

Michel Marcus: No, you're right.

15:48

Michel Marcus: Or like this ? for 3 < p prime <= prime(n) ?

15:48

Michel Marcus: Or better ? for 5 <= p prime <= prime(n)

#10 by Michael De Vlieger at Mon Apr 11 08:20:55 EDT 2016

STATUS

editing

proposed

Discussion

Mon Apr 11

14:42

Alois P. Heinz: The formula is not clear to me.  p runs over all primes >3? Until infinity?

#9 by Michael De Vlieger at Mon Apr 11 08:20:53 EDT 2016

MATHEMATICA

Table[Product[Prime@ k - 2, {k, 3, n}] - 2 Product[Prime@ k - 3, {k, 3, n}] + Product[Prime@ k - 4, {k, 3, n}], {n, 21}] (* Michael De Vlieger, Apr 11 2016 *)

STATUS

proposed

editing