A261016 a(n) = Sum_{k=0..2^n-1} k*A261015(n,k).

1, 6, 18, 46, 107, 241, 535, 1178, 2569, 5546, 11859, 25156, 53058, 111379, 232966, 486023, 1012185, 2104729, 4370644, 9064924, 18778766, 38856079, 80307630, 165790125, 341872016, 704171185, 1448812630, 2977673003, 6113469501, 12538958895, 25693167881, 52598980642

Offset: 1

Author

N. J. A. Sloane, Aug 16 2015

Keywords

• nonn

Comments

The scaled values a(n)/2^n are (to nine decimal places) 0.5000000000, 1.500000000, 2.250000000, 2.875000000, 3.343750000, 3.765625000, 4.179687500, 4.601562500, 5.017578125, 5.416015625, 5.790527344, 6.141601562, 6.476806641, 6.798034668, 7.109558105, 7.416122437, 7.722358704, 8.028903961, 8.336341858, 8.644985199, 8.954413414, 9.264011145, 9.573415518, 9.881861508, 10.18858004, 10.49296834, 10.79449527, 11.09269635, 11.38722431, 11.67781548, 11.96431363, 12.24665452, ...

Links

• Alois P. Heinz and Hiroaki Yamanouchi, Table of n, a(n) for n = 1..58 (a(1)-a(36) from Alois P. Heinz)

Crossrefs

Cf. A261019, A261015, A260273.

Programs

Haskell

a261016 = sum . zipWith (*) [0..] . a261019_row'
-- Reinhard Zumkeller, Aug 18 2015

Mathematica

(* This program is not suitable to compute more than a dozen terms. *)
notVis[bits_] := For[i = 0, True, i++, If[SequencePosition[bits, IntegerDigits[i, 2]] == {}, Return[i]]];
T[n_, k_] := Select[Rest[IntegerDigits[#, 2]] & /@ Range[2^n, 2^(n+1) - 1], notVis[#] == k &] // Length;
a[n_] := Sum[k*T[n, k], {k, 0, 2^n - 1}];
Table[an = a[n]; Print["a(", n, ") = ", an]; an, {n, 1, 12}] (* Jean-François Alcover, Aug 02 2018 *)

Extensions

a(5)-a(16) from Alois P. Heinz, Aug 17 2015

a(17)-a(25) from Reinhard Zumkeller, Aug 18 2015

a(26)-a(32) from Alois P. Heinz, Aug 19 2015