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A277831 Number of '1' digits in the set of all numbers from 0 to A014824(n) = Sum_{i=1..n} i*10^(n-i) = (0, 1, 12, 123, 1234, 12345, ...).

%I A277831 #23 Jan 01 2021 11:47:35
%S A277831 0,1,5,57,689,8121,93553,1058985,11824417,130589849,1429355281,
%T A277831 15528120716,167626886179,1799725651922,19231824420465,
%U A277831 204663923217008,2170096022293551,22935528124170094,241700960254046637,2540466392663923180,26639231827873799724
%N A277831 Number of '1' digits in the set of all numbers from 0 to A014824(n) = Sum_{i=1..n} i*10^(n-i) = (0, 1, 12, 123, 1234, 12345, ...).
%H A277831 David A. Corneth, <a href="/A277831/b277831.txt">Table of n, a(n) for n = 0..998</a>
%H A277831 M. F. Hasler, <a href="https://oeis.org/wiki/User_talk:M._F._Hasler/Digits_d_in_0_through_123...n">"Digits d in 0 through 123...n"</a>, OEIS Wiki, Nov. 2016.
%F A277831 a(n) = A277832(n) + 3*10^(n-2), for 2 <= n <= 10.
%F A277831 More generally, for m = 0, ..., 9, let a[m] denote A277830, ..., A277838 and A277849, respectively. Then a[0](n) = a[n](n) = a[m](n) + 1 for all m > n >= 0, and a[m-1](n) = a[m](n) + (m+1)*10^(n-m) for all n >= m > 1.
%e A277831 For n=2 are counted the same '1' as for n=1, plus the 4 additional digits '1' in 10, 11 and 12.
%o A277831 (PARI) print1(c=N=0);for(n=1,8,print1(","c+=sum(k=N+1,N=N*10+n,#select(d->d==1,digits(k)))))
%o A277831 (PARI) A277831(n)=if(n<2,n, n<11, A277832(n)+3*10^(n-2), error("n > 10 not yet implemented")) \\ _M. F. Hasler_, Nov 02 2016, edited Dec 28 2020
%Y A277831 Cf. A277830 - A277838, A277849, A277635, A272525, A083449, A014824.
%K A277831 nonn,base
%O A277831 0,3
%A A277831 _M. F. Hasler_, Nov 01 2016
%E A277831 More terms from _Lars Blomberg_, Nov 05 2016
%E A277831 Removed incorrect b-file. - _David A. Corneth_, Dec 31 2020