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A113840
Palindromes that are sandwiched between a prime and a powerful(1) number, in any order.
0
2, 3, 8, 242, 676, 42024, 625946649526, 678176310013671876
OFFSET
1,1
COMMENTS
Here we are considering powerful numbers (first definition) A001694. Note that, by definition, 1 is powerful.
a(9) > 10^18. [From Donovan Johnson, Oct 01 2009]
LINKS
Eric Weisstein's World of Mathematics, Powerful Number.
EXAMPLE
42023 prime, 42024 palindrome, 42025=5^2*41^2 powerful(1).
625946649525=3^2*5^2*29^2*149^3 powerful(1), 625946649526 palindrome, 625946649527 prime.
CROSSREFS
Sequence in context: A112237 A371225 A132502 * A336292 A285088 A075849
KEYWORD
base,hard,nonn
AUTHOR
Giovanni Resta, Jan 24 2006
EXTENSIONS
a(8) from Donovan Johnson, Oct 01 2009
STATUS
approved