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 A281783 #7 Feb 01 2017 16:52:30
%S A281783 1,2,3,5,7,9,12,16,19,21,23,25,27,30,34,39,45,50,54,57,60,63,65,66,67,
%T A281783 68,70,73,76,79,82,86,91,97,104,110,115,119,122,124,126,128,130,132,
%U A281783 134,136,139,143,148,154,161,167,172,176,179,182,185,188,192,197
%N A281783 a(n)=index of first term of n-th run of consecutive terms in arithmetic progression in A281579.
%C A281783 This sequence is strictly increasing.
%C A281783 For any n>0, a(n+1)=index of last term of n-th run of consecutive terms in arithmetic progression in A281579.
%H A281783 Rémy Sigrist, <a href="/A281783/b281783.txt">Table of n, a(n) for n = 1..10000</a>
%F A281783 a(n)=2-n+Sum_{k=1..n-1} A281579(k) for any n>0.
%Y A281783 Cf. A281579.
%K A281783 nonn
%O A281783 1,2
%A A281783 _Rémy Sigrist_, Jan 29 2017