A293725 Numbers k such that c(k,0) = c(k,1), where c(k,d) = number of d's in the first k digits of the base-2 expansion of sqrt(2).
2, 10, 20, 24, 28, 32, 318, 328, 330, 334, 336, 608, 622, 636, 638, 674, 676, 678, 680, 682, 826, 828, 832, 836, 838, 842, 844, 846, 848, 850, 852, 856, 858, 876, 880, 884, 886, 898, 906, 908, 918, 920, 928, 930, 942, 944, 946, 948, 950, 962, 964, 966, 968
Offset: 1
Examples
In base 2, sqrt(2) = 1.0110101000001001111001..., so that initial segments 1.0; 1.011010100..., of lengths 2,10,... have the same number of 0's and 1's.
Programs
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Mathematica
z = 300; u = N[Sqrt[2], z]; d = RealDigits[u, 2][[1]]; t[n_] := Take[d, n]; c[0, n_] := Count[t[n], 0]; c[1, n_] := Count[t[n], 1]; Table[{n, c[0, n], c[1, n]}, {n, 1, 100}] u = Select[-1 + Range[z], c[0, #] == c[1, #] &] (* A293725 *) u/2 (* A293726 *) Select[-1 + Range[z], c[0, #] < c[1, #] &] (* A293727 *) Select[-1 + Range[z], c[0, #] > c[1, #] &] (* A293728 *)
Comments