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A103159 a(n) = GCD(reverse(n), reversed(n+1)). 1
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 5, 5, 5, 5, 5, 5, 5, 5, 5, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,20

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = GCD(A004086(n), A004086(n+1)).

MATHEMATICA

rd[x_] :=FromDigits[Reverse[IntegerDigits[x]]] Table[GCD[rd[w], rd[w+1]], {w, 1, 100}]

PROG

(Python)

from math import gcd

def a(n): return gcd(int(str(n)[::-1]), int(str(n+1)[::-1]))

print([a(n) for n in range(1, 106)]) # Michael S. Branicky, Dec 12 2021

CROSSREFS

Cf. A004086.

Sequence in context: A215887 A159451 A336682 * A063056 A174835 A297036

Adjacent sequences:  A103156 A103157 A103158 * A103160 A103161 A103162

KEYWORD

base,nonn

AUTHOR

Labos Elemer, Jan 25 2005

STATUS

approved

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Last modified September 26 10:50 EDT 2022. Contains 356997 sequences. (Running on oeis4.)