The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A317824 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A317824

a(n) = A000422(n)^^A000422(n) (mod 10^len(A000422(n))), where ^^ indicates tetration or hyper-4 (e.g., 3^^4 = 3^(3^(3^3))).
(history; published version)

#79 by N. J. A. Sloane at Sun Sep 12 12:46:27 EDT 2021

STATUS

proposed

approved

#78 by Michel Marcus at Sun Sep 12 10:01:24 EDT 2021

STATUS

editing

proposed

#77 by Michel Marcus at Sun Sep 12 09:44:24 EDT 2021

CROSSREFS

Cf. A000422, A058183, A171882 (tetration), A317903.

#76 by Michel Marcus at Sun Sep 12 09:42:55 EDT 2021

REFERENCES

M. Marco Ripà, La strana coda della serie n^n^...^n, Trento, UNI Service, Nov 2011, page 60. ISBN 978-88-6178-789-6

LINKS

M. Marco Ripà, <a href="https://www.researchgate.net/publication/328493277_On_the_Convergence_Speed_of_Tetration">On the Convergence Speed of Tetration</a>, ResearchGate (2018).

PROG

(PARI) tmod(b, n) = {if (b % n == 0, return (0)); if (b % n == 1, return (1)); if (gcd(b, n)==1, return (lift(Mod(b, n)^tmod(b, lift(znorder(Mod(b, n))))))); lift(Mod(b, n)^(eulerphi(n) + tmod(b, eulerphi(n)))); }

f(n) = my(t=n); forstep(k=n-1, 1, -1, t=t*10^#Str(k)+k); t; \\ A000422

a(n) = my(x=f(n)); tmod(x, 10^#Str(x)); \\ Michel Marcus, Sep 12 2021

STATUS

proposed

editing

Discussion

Sun Sep 12

09:43

Michel Marcus: using code for A347560

#75 by Michel Marcus at Sat Sep 11 05:37:08 EDT 2021

STATUS

editing

proposed

#74 by Michel Marcus at Sat Sep 11 05:37:04 EDT 2021

CROSSREFS

Cf. A000422, A058183, A171882 (tetration).

STATUS

proposed

editing

#73 by Michel Marcus at Sat Sep 11 05:11:53 EDT 2021

STATUS

editing

proposed

#72 by Michel Marcus at Sat Sep 11 05:10:48 EDT 2021

CROSSREFS

Cf. A000422, A058183, A171882.

STATUS

approved

editing

Discussion

Sat Sep 11

05:11

Michel Marcus: replace len(A000422(n)) with A058183  (3 times) ? or leave as is ??

#71 by Michel Marcus at Sun Aug 30 03:37:00 EDT 2020

STATUS

reviewed

approved

#70 by Joerg Arndt at Sun Aug 30 02:49:25 EDT 2020

STATUS

proposed

reviewed