This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A173527 #17 May 12 2019 03:04:26
%S A173527 1,2,3,4,5,6,7,2,3,4,5,6,7,8,3,4,5,6,7,8,9,4,5,6,7,8,9,10,5,6,7,8,9,
%T A173527 10,11,6,7,8,9,10,11,12,7,8,9,10,11,12,13,2,3,4,5,6,7,8,3,4,5,6,7,8,9,
%U A173527 4,5,6,7,8,9,10,5,6,7,8,9,10,11,6,7,8,9,10,11,12,7,8,9,10,11,12,13,8,9,10,11,12,13,14,3,4
%N A173527 a(n) = 1 + A053828(n-1), where A053828 is the sum of digits in base 7.
%C A173527 If A053828 is regarded as a triangle then the rows converge to this sequence, i.e., a(n) = A053828(7^k+n-1) in the limit k->infinity, where k plays the role of a row index in A053828.
%C A173527 See conjecture in the entry A000120.
%C A173527 This is the case for base b=7 for the sum of digits. A063787 and A173523 to A173526 deal with the bases 2 to 6. A173525 contains generic remarks concerning these 8 sequences which look in equivalent ways at their sum of digits as a sequence with triangular structure.
%F A173527 a(n) = A053828(7^k+n-1) where k >= ceiling(log_7(n/6)). [_R. J. Mathar_, Dec 09 2010]
%F A173527 Conjecture: Fixed point of the morphism 1->{1,2,3,...b}, 2->{2,3,4...,b+1}, j->{j,j+1,...,j+b-1} for b=7. [_Joerg Arndt_, Dec 08 2010]
%p A173527 A053828 := proc(n) add(d, d=convert(n,base,7)) ; end proc:
%p A173527 A173527 := proc(n) local b; b := 7 ; if n < b then n; else k := n/(b-1); k := ceil(log(k)/log(b)) ; A053828(b^k+n-1) ; end if; end proc:
%p A173527 seq(A173527(n),n=1..100) ; # _R. J. Mathar_, Dec 09 2010
%t A173527 Table[Total[IntegerDigits[n-1,7]]+1,{n,110}] (* _Harvey P. Dale_, Apr 01 2018 *)
%Y A173527 Cf. A000120, A053828, A063787.
%Y A173527 Cf. A173523, A173524, A173525, A173526, A173528, A173529.
%K A173527 nonn,base
%O A173527 1,2
%A A173527 _Omar E. Pol_, Feb 20 2010
%E A173527 More terms from _Vincenzo Librandi_, Feb 21 2010