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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
OFFSET
1,20
LINKS
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: A159451 A378865 A336682 * A063056 A174835 A297036
KEYWORD
base,nonn
AUTHOR
Labos Elemer, Jan 25 2005
STATUS
approved