A027579 Numbers n such that n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2 is palindromic.

1, 99, 331, 3207, 10099, 105720053635, 10310949321253

Offset: 1

Author

Patrick De Geest

Keywords

• nonn
• base
• more

Comments

All terms are odd. - Chai Wah Wu, Jan 18 2016

Links

• P. De Geest, Palindromic Sums of Squares of Consecutive Integers

Crossrefs

Cf. A027580.

Programs

Mathematica

Select[Range[15000],PalindromeQ[5(6+4#+#^2)]&] (* The program uses the PalindromeQ function from Mathematica version 10.3 *) (* Harvey P. Dale, Nov 02 2015 *)

PARI

isok(n) = my(d = digits(n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2)); d == Vecrev(d); \\ Michel Marcus, Jan 24 2016

Extensions

a(6) from Chai Wah Wu, Jan 18 2016

a(7) from Giovanni Resta, Aug 04 2019