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%I #30 Sep 08 2022 08:44:57
%S 1,13,146,1610,17715,194871,2143588,23579476,259374245,2853116705,
%T 345227121316,41772481679248,5054470283189021,611590904265871555,
%U 74002499416170458170,8954302429356625438586,1083470593952151678068923,131099941868210353046339701
%N Take the first n numbers written in base 11, concatenate them, then convert from base 11 to base 10.
%H Vincenzo Librandi, <a href="/A048442/b048442.txt">Table of n, a(n) for n = 1..200</a>
%e a(11) = (1)(2)(3)(4)(5)(6)(7)(8)(9)(A)(10) = 123456789A10_11 = 345227121316.
%t If[STARTPOINT==1, n={}, n=Flatten[IntegerDigits[Range[STARTPOINT-1], 11]]]; Table[AppendTo[n, IntegerDigits[w, 11]]; n=Flatten[n]; FromDigits[n, 11], {w, STARTPOINT, ENDPOINT}] (* _Dylan Hamilton_, Aug 11 2010 *)
%t f[n_]:= FromDigits[Flatten@IntegerDigits[Range@n, 11], 11]; Array[f, 20] (* _Vincenzo Librandi_, Dec 30 2012 *)
%o (PARI) { cuo=0;
%o for(ixp=1, 18, casi = ixp; cvst=0;
%o while(casi != 0,
%o cvd = casi%11; cvst=100*cvst + cvd + 1; casi = (casi - cvd) / 11 );
%o while(cvst !=0, ptch = cvst%100;
%o cuo=cuo*11+ptch-1; cvst = (cvst - ptch) / 100 ); print1(cuo, ", "))}
%o \\ _Douglas Latimer_, May 09 2012
%o (Magma) [n eq 1 select 1 else Self(n-1) * 11^(1+Ilog(11, n)) + n: n in [1..20]]; // _Vincenzo Librandi_, Dec 30 2012
%Y Cf. A014881.
%Y Concatenation of first n numbers in other bases: 2: A047778, 3: A048435, 4: A048436, 5: A048437, 6: A048438, 7: A048439, 8: A048440, 9: A048441, 10: A007908, 11: this sequence, 12: A048443, 13: A048444, 14: A048445, 15: A048446, 16: A048447.
%K nonn,base,easy
%O 1,2
%A _Patrick De Geest_, May 15 1999
%E 1 more term from _Douglas Latimer_, May 10 2012
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