A093849 - OEIS

%I #13 Sep 08 2022 08:45:13

%S 9,153,2097,26496,319995,3749994,42999985,484999992,5399999991,

%T 59499999990,649999999935,7049999999988,75999999999924,

%U 814999999999941,8699999999999985,92499999999999984,979999999999999902

%N Row sums of triangle A093846.

%H G. C. Greubel, <a href="/A093849/b093849.txt">Table of n, a(n) for n = 1..990</a>

%F a(n) = n*(2*10^(n-1) - 2 + (n+1)*floor(9*10^(n-1)/n))/2.

%t Table[n*(2*10^(n-1) -2 +(n+1)*Floor[9*10^(n-1)/n])/2, {n, 1, 20}] (* _G. C. Greubel_, Mar 22 2019 *)

%o (PARI) {a(n) = n*(2*10^(n-1) -2 +(n+1)*floor(9*10^(n-1)/n))/2}; \\ _G. C. Greubel_, Mar 22 2019

%o (Magma) [n*(2*10^(n-1) -2 +(n+1)*Floor(9*10^(n-1)/n))/2: n in [1..20]]; // _G. C. Greubel_, Mar 22 2019

%o (Sage) [n*(2*10^(n-1) -2 +(n+1)*floor(9*10^(n-1)/n))/2 for n in (1..20)] # _G. C. Greubel_, Mar 22 2019

%Y Cf. A093846.

%K base,easy,nonn

%O 1,1

%A _Amarnath Murthy_, Apr 18 2004

%E Edited and extended by _David Wasserman_, Mar 26 2007