A139258 Palindromes formed from the reflected decimal expansion of Euler's constant (or Euler-Mascheroni constant) gamma.

5, 55, 575, 5775, 57775, 577775, 5772775, 57722775, 577212775, 5772112775, 57721512775, 577215512775, 5772156512775, 57721566512775, 577215666512775, 5772156666512775, 57721566466512775, 577215664466512775

Offset: 1

Author

Omar E. Pol, May 01 2008

Keywords

• easy
• nonn
• base

Examples

			n ... Successive digits of a(n)
1 ............ ( 5 )
2 ......... . ( 5 5 )
3 .......... ( 5 7 5 )
4 ......... ( 5 7 7 5 )
5 ........ ( 5 7 7 7 5 )
6 ....... ( 5 7 7 7 7 5 )
7 ...... ( 5 7 7 2 7 7 5 )
8 ..... ( 5 7 7 2 2 7 7 5 )
9 .... ( 5 7 7 2 1 2 7 7 5 )
10 .. ( 5 7 7 2 1 1 2 7 7 5 )
		

Crossrefs

Decimal expansion of gamma: A001620. Cf. A135634, A135697, A135700, A139259, A139260, A139261.

Programs

Mathematica

a[n_]:=FromDigits[Join[RealDigits[EulerGamma,10,Ceiling[n/2]][[1]],Reverse[RealDigits[EulerGamma,10,Floor[n/2]][[1]]]]];Array[a,18] (* James C. McMahon, Jun 29 2025 *)