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

1,1

Comments

Also, successive digits of A139258.

Links

Table of n, a(n) for n=1..78.

Example

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

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 *)

Crossrefs

Decimal expansion of gamma: A001620.

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

Sequence in context: A369340 A368870 A076568 * A105444 A391582 A240233

Adjacent sequences: A139256 A139257 A139258 * A139260 A139261 A139262

Keyword

easy,nonn,tabl,base

Author

Omar E. Pol, May 01 2008

Status

approved