login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A171407 This is a sequence demonstrating a congruence property of second order exponential functions. Let f(n) = a^(b^n) + c where a,b,c & n belong to N, a, b & c fixed. Then f(n + k*phi(phi(f(n)) is congruent to 0 (mod(f(n)). Here k belongs to N. This is a sequence of quotients generated by f(n + k*f(n))/f(n) when a & b = 2, c= 3 and n = 1. when a & b = 2 and c =3 when n = 1. 0
37, 613566757, 48611766702991209066196372490252601637 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..3.

EXAMPLE

a(n) = 2^2^n + 3 = 7 when n = 1. phi(phi(7)) = 2. 2^2^(1 + 2*k) + 3 = 259; 259/7 = 37.

PROG

(PARI) a(k)=(2^2^(1 + 2*k) + 3)/7

CROSSREFS

Sequence in context: A238840 A345467 A329226 * A023930 A022072 A351221

Adjacent sequences:  A171404 A171405 A171406 * A171408 A171409 A171410

KEYWORD

nonn,uned,bref

AUTHOR

A.K. Devaraj, Dec 08 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 3 07:58 EDT 2022. Contains 355031 sequences. (Running on oeis4.)