A139259 Triangle read by rows: row n lists the digits of A139258(n), the palindromic number formed from the reflected decimal expansion of Euler's constant (or Euler-Mascheroni constant) gamma.

5, 5, 5, 5, 7, 5, 5, 7, 7, 5, 5, 7, 7, 7, 5, 5, 7, 7, 7, 7, 5, 5, 7, 7, 2, 7, 7, 5, 5, 7, 7, 2, 2, 7, 7, 5, 5, 7, 7, 2, 1, 2, 7, 7, 5, 5, 7, 7, 2, 1, 1, 2, 7, 7, 5, 5, 7, 7, 2, 1, 5, 1, 2, 7, 7, 5, 5, 7, 7, 2, 1, 5, 5, 1, 2, 7, 7, 5

Offset: 1

Author

Omar E. Pol, May 01 2008

Keywords

• easy
• nonn
• tabl
• base

Comments

Also, successive digits of A139258.

Examples

			Triangle begins:
....... 5
...... 5,5
..... 5,7,5
.... 5,7,7,5
... 5,7,7,7,5
		

Crossrefs

Decimal expansion of gamma: A001620.

Cf. A138068, A138070, A138072, A139258, A139260, A139261.

Programs

Mathematica

a[n_]:=FromDigits[Join[RealDigits[EulerGamma,10,Ceiling[n/2]][[1]],Reverse[RealDigits[EulerGamma,10,Floor[n/2]][[1]]]]];IntegerDigits/@Array[a,12]//Flatten (* James C. McMahon, Jun 29 2025 *)