This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A008566 #26 Mar 23 2025 03:57:05 %S A008566 1,5,2,5,1,2,5,6,2,5,3,1,2,5,1,5,6,2,5,7,8,1,2,5,3,9,0,6,2,5,1,9,5,3, %T A008566 1,2,5,9,7,6,5,6,2,5,4,8,8,2,8,1,2,5,2,4,4,1,4,0,6,2,5,1,2,2,0,7,0,3, %U A008566 1,2,5,6,1,0,3,5,1,5,6,2,5,3,0,5,1,7,5,7,8,1,2,5,1,5,2,5,8,7,8 %N A008566 Digits of powers of 5. %C A008566 Irregular table with row length sequence A210435. - _Jason Kimberley_, Nov 26 2012 %C A008566 The constant whose decimal expansion is this sequence is irrational (Mahler, 1981). - _Amiram Eldar_, Mar 23 2025 %H A008566 Seiichi Manyama, <a href="/A008566/b008566.txt">Rows n = 0..100, flattened</a> %H A008566 Kurt Mahler, <a href="https://doi.org/10.1016/0022-314X(81)90010-X">On some irrational decimal fractions</a>, Journal of Number Theory, Vol. 13, No. 2 (1981), pp. 268-269. %e A008566 Triangle begins: %e A008566 1; %e A008566 5; %e A008566 2, 5; %e A008566 1, 2, 5; %e A008566 6, 2, 5; %e A008566 3, 1, 2, 5; %e A008566 1, 5, 6, 2, 5; %e A008566 7, 8, 1, 2, 5, %e A008566 3, 9, 0, 6, 2, 5; %e A008566 ... %t A008566 Flatten[IntegerDigits/@(5^Range[0,20])] (* _Harvey P. Dale_, Jan 18 2012 *) %Y A008566 Cf. A000351, A210435. %Y A008566 Cf. A000455, A008564, A008565, A008567, A008568, A008569, A008570, A008571, A008572, A008573, A010054. %K A008566 nonn,base,easy,tabf %O A008566 0,2 %A A008566 _N. J. A. Sloane_