A190411 Decimal expansion of sum of even-numbered columns of array G defined at A190404.

2, 9, 1, 3, 4, 0, 9, 8, 6, 8, 8, 2, 7, 6, 3, 2, 8, 4, 6, 3, 0, 3, 5, 1, 4, 0, 7, 9, 4, 7, 3, 2, 3, 6, 6, 6, 7, 9, 8, 4, 0, 3, 0, 5, 8, 6, 7, 9, 5, 9, 4, 9, 0, 2, 7, 1, 1, 2, 9, 5, 6, 2, 6, 7, 8, 5, 6, 5, 3, 5, 6, 4, 8, 3, 1, 5, 2, 5, 2, 6, 4, 0, 0, 1, 1, 0, 3, 3, 2, 1, 0, 5, 5, 5, 7, 5, 6, 0, 1, 9, 3, 2, 5, 2, 9, 6, 7, 9, 9, 0, 7, 9, 6, 5, 9, 0

Offset: 0

Author

Clark Kimberling, May 10 2011

Keywords

• nonn
• cons

Comments

See A190404.

Examples

			0.29134098688276328463035140794732366679840305867959490...
		

Links

• Danny Rorabaugh, Table of n, a(n) for n = 0..500

Crossrefs

Cf. A190404, A190410.

Programs

Mathematica

f[i_, j_] :=  i + (j + i - 2)(j + i - 1)/2; (* natural number array, A000027 *)
g[i_, j_] := (1/2)^f[i, j];
c[j_] := Sum[g[i,j], {i,1,400}]; (* j-th column sum of G *)
c1 = N[Sum[c[2 i - 1], {i, 1, 10}], 60]
RealDigits[c1, 10, 60, -1]  (* A190410 *)
c2 = N[Sum[c[2 i], {i, 1, 10}], 60]
RealDigits[c2, 10, 60, -1]  (* A190411 *)
c1 + c2 (* very close to 1 *)

Extensions

a(69)-a(79) corrected and a(80)-a(115) added by Danny Rorabaugh, Mar 26 2015