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 A063762 #21 Oct 06 2024 09:16:06
%S A063762 4,6,9,10,14,15,20,21,22,25,26,28,33,34,35,38,39,42,44,46,49,51,52,55,
%T A063762 57,58,62,65,66,68,69,74,76,77,78,82,85,86,87,88,91,92,93,94,95,99,
%U A063762 102,104,106,110,111,114,115,116,117,118,119,121,122,123,124,129,130,133
%N A063762 Sqrt(n)-rough nonprimes: largest prime factor of n (A006530) >= sqrt(n).
%C A063762 A positive integer is called y-rough if all its prime factors are >= y.
%D A063762 D. H. Greene and D. E. Knuth, Mathematics for the Analysis of Algorithms; see pp. 95-98.
%H A063762 Ray Chandler, <a href="/A063762/b063762.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Harry J. Smith)
%H A063762 Beeler, M., Gosper, R. W. and Schroeppel, R., <a href="http://www.inwap.com/pdp10/hbaker/hakmem/number.html#item29">HAKMEM, ITEM 29</a>
%t A063762 Select[ Range[ 2, 150 ], !PrimeQ[ # ] && FactorInteger[ # ] [ [ -1, 1 ] ] >= Sqrt[ # ] & ]
%o A063762 (PARI) { n=0; for (m=2, 10^9, f=vecmax(component(factor(m), 1)); if(!isprime(m) && f^2 >= m, write("b063762.txt", n++, " ", m); if (n==1000, break)) ) } \\ _Harry J. Smith_, Aug 30 2009
%o A063762 (Python)
%o A063762 from math import isqrt
%o A063762 from sympy import primepi
%o A063762 def A063762(n):
%o A063762 def f(x): return int(n+(x if x<=3 else x-primepi(x//(y:=isqrt(x)))-sum(primepi(x//i)-primepi(i) for i in range(2,y))))
%o A063762 m, k = n, f(n)
%o A063762 while m != k: m, k = k, f(k)
%o A063762 return m # _Chai Wah Wu_, Oct 05 2024
%Y A063762 Cf. A006530, A063538, A063539, A063763.
%K A063762 nonn
%O A063762 1,1
%A A063762 _Robert G. Wilson v_, Aug 14 2001