A224848 Reverse concatenation of the square of first a(n) integers gives a prime.

2, 3, 14, 700, 2818

Offset

1,1

Comments

The number corresponding to a(5) = 2818 is a probable prime of 18269 digits. - Giovanni Resta, Jul 25 2013

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 3742-digit 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