A113840 Palindromes that are sandwiched between a prime and a powerful(1) number, in any order.

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

Table of n, a(n) for n=1..8.

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

Cf. A001694, A002113.

Sequence in context: A112237 A371225 A132502 * A336292 A285088 A075849

Adjacent sequences: A113837 A113838 A113839 * A113841 A113842 A113843

Keyword

base,hard,nonn

Author

Giovanni Resta, Jan 24 2006

Extensions

a(8) from Donovan Johnson, Oct 01 2009

Status

approved