A185635 Fixed points of A075075.

1, 2, 8, 36, 39, 49, 370, 626, 632, 1030, 13155, 32317, 61358, 86704, 2535431, 13360009

Offset

1,2

Comments

A075075(a(n)) = A160516(a(n)) = a(n);

A075075(a(n)-1) * A075075(a(n)+1) mod a(n) = 0.

Links

Table of n, a(n) for n=1..16.

Prog

(Haskell)
a185635 n = a185635_list !! (n-1)
a185635_list = filter (> 0) $
   zipWith (\x y -> if x == y then y else 0) [1..] a075075_list
-- Reinhard Zumkeller, Dec 19 2012
(Python)
from math import gcd
A185635_list, l1, l2, m, b = [1, 2], 2, 1, 2, {1, 2}
for n in range(3, 10**4):
    i = m
    while True:
        if not i in b:
            if n == i:
                A185635_list.append(i)
            l1, l2, m = i, l1, i//gcd(l1, i)
            b.add(i)
            break
        i += m # Chai Wah Wu, Dec 09 2014

Crossrefs

Sequence in context: A007508 A122674 A203762 * A076122 A332607 A236626

Adjacent sequences: A185632 A185633 A185634 * A185636 A185637 A185638

Keyword

nonn,more

Author

Reinhard Zumkeller, Dec 19 2012

Extensions

a(15) from Chai Wah Wu, Dec 10 2014

a(16) from Chai Wah Wu, Sep 22 2019

Status

approved