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 A240528 #22 Sep 08 2022 08:46:07
%S A240528 63,80,128,256,287,288,319,320,324,383,399,440,447,480,495,539,560,
%T A240528 567,576,608,640,648,671,675,703,720,729,799,831,863,927,935,972,975,
%U A240528 1000,1007,1055,1056,1071,1079,1080,1104,1119,1120,1160,1175,1183,1184
%N A240528 Indices of 8-almost prime triangular numbers.
%H A240528 Muniru A Asiru, <a href="/A240528/b240528.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Vincenzo Librandi)
%F A240528 { m : A069904(m) = 8 }. - _Alois P. Heinz_, Aug 05 2019
%e A240528 a(1) = 63 because A000217(63) = 63*(63+1)/2 = 2016 = 2^5 * 3^2 * 7 is an 8-almost prime.
%t A240528 Flatten[Position[Accumulate[Range[1500]], _?(PrimeOmega[#]== 8 &)]]
%o A240528 (GAP) F:=List([1..1200],n->Length(Factors(n*(n+1)/2)));; a:=Filtered([1..Length(F)],i->F[i]=8); # _Muniru A Asiru_, Dec 22 2018
%o A240528 (Magma) [n: n in [2..1200] | &+[d[2]: d in Factorization((n*(n+1)))] eq 9]; // _Vincenzo Librandi_, Dec 22 2018
%Y A240528 Cf. A000217, A069904, A108815, A114435, A114436, A114437, A164977.
%Y A240528 Cf. A046310 (8-almost primes).
%K A240528 nonn
%O A240528 1,1
%A A240528 _Vincenzo Librandi_, Apr 07 2014