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 A061536 #34 Mar 12 2021 06:19:12
%S A061536 1,2,4,6,9,12,16,20,24,28,33,38,44,50,56,62,69,76,84,92,100,108,117,
%T A061536 126,135,144,153,162,172,182,193,204,215,226,237,248,260,272,284,296,
%U A061536 309,322,336,350,364,378,393,408,423,438,453,468,484,500,516,532,548
%N A061536 a(1) = 1 and a(n) = a(n-1) + (the number of primes <= n) for n > 1.
%H A061536 Harry J. Smith, <a href="/A061536/b061536.txt">Table of n, a(n) for n = 1..1000</a>
%F A061536 a(n) = 1 + A046992(n).
%t A061536 a[1] = 1; a[n_] := a[n - 1] + PrimePi[n]; Table[ a[n], {n, 1, 70} ]
%t A061536 Accumulate[PrimePi[Range[60]]]+1 (* _Harvey P. Dale_, Jun 11 2014 *)
%o A061536 (PARI) a=1; for (n=1, 100, print1(a+=primepi(n), ", ")) \\ _Harry J. Smith_, Jul 24 2009
%o A061536 (PARI) first(n)=my(p,s=1); vector(n,k, s+=p+=isprime(k)) \\ _Charles R Greathouse IV_, Jan 06 2016
%Y A061536 Cf. A000720, A046992.
%K A061536 nonn,easy
%O A061536 1,2
%A A061536 _R. K. Guy_, _Robert G. Wilson v_, May 14 2001
%E A061536 Definition edited by _Georg Fischer_, Sep 04 2020