%I
%S 13,148,1003,16141,117547,917053,15502289,114274754,909482399,
%T 15471962269,115061008452,917885746619,15675637954053,116877859994048,
%U 933643385166035,15975162211603393,119196492782053456,952870691477908028,16319572144410372393,121792577413939691253
%N Sum of all ndigit Stern numbers.
%e Sum of all 1digit Stern numbers is 1 + 1 + 2 + 3 + 6 = 13.
%e Sum of all 2digit Stern numbers is 11 + 20 + 40 + 77 = 148.
%e Sum of all 3digit Stern numbers is 148 + 285 + 570 = 1003.
%t stern[1] = 1; stern[n_] := stern[n] = Sum[stern[k], {k, n  Ceiling[(Sqrt[8*n 7]1)/2], n1}]; digNum[n_] := Length @ IntegerDigits[n]; digCount = 0; sum = 0; cumsum = {}; Do[s = stern[n]; If[digNum[s] > digCount, digCount++; AppendTo[cumsum, sum]]; sum += s, {n, 1, 25}]; Differences[cumsum] (* _Amiram Eldar_, Nov 30 2019 *)
%Y Cf. A005230.
%K nonn,base,less
%O 1,1
%A _Parthasarathy Nambi_, Nov 01 2007
%E More terms from _Amiram Eldar_, Nov 30 2019
