

A224848


Reverse concatenation of the square of first a(n) integers gives a prime.


0




OFFSET

1,1


COMMENTS

The number corresponding to a(5) = 2818 is a probable prime of 18269 digits.  Giovanni Resta, Jul 25 2013
The number corresponding to a(5) = 2818 is prime (definite, not probable), according to Wolfram Mathematica 11.0 and Maple 2018.  Kellen Myers, Dec 04 2019


LINKS

Table of n, a(n) for n=1..5.


EXAMPLE

a(4) = 700 because reverse concatenation of squares of 1 to 700 gives 490000488601......2516941 which is a 3742digit prime number.


CROSSREFS

Cf. A091314.
Sequence in context: A101003 A042071 A042817 * A271330 A262462 A180698
Adjacent sequences: A224845 A224846 A224847 * A224849 A224850 A224851


KEYWORD

nonn,hard,more,base


AUTHOR

Shyam Sunder Gupta, Jul 22 2013


EXTENSIONS

a(5) from Giovanni Resta, Jul 25 2013


STATUS

approved



