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 A145915 #4 Feb 16 2025 08:33:09
%S A145915 146,164,458,524,584,626,764,956,1084,1172,1322,1478,1858,1934,2138,
%T A145915 2174,2336,2966,3158,3464,3548,3566,3884,3974,3998,4124,4274,4346,
%U A145915 4696,5042,5102,5246,5354,5414,6002,6038,6434,6626,6646,6782,6884,7034,7094
%N A145915 Even composites in A145832.
%C A145915 A145832 is the sequence of numbers n such that for each divisor d of n, k = d + n/d is square-root smooth, i.e. p <= sqrt(k), where p is the largest prime dividing k.
%H A145915 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RoundNumber.html">Round Number</a>
%e A145915 146 = 2*73 is even and composite, 1, 2, 73, 146 are its divisors. 1+146/1 = 146+146/146 = 147 = 3*7^2 and 7 < 12 < sqrt(147); 2+146/2 = 73+146/73 = 75 = 3*5^2 and 5 < 8 < sqrt(75). Hence 146 is in the sequence.
%o A145915 (Magma) [ n: n in [4..7100 by 2] | forall{ k: k in [ Integers()!(d+n/d): d in [ D[j]: j in [1..a] ] ] | k ge (IsEmpty(T) select 1 else Max(T) where T is [ x[1]: x in Factorization(k) ])^2 } where a is IsOdd(#D) select (#D+1)/2 else #D/2 where D is Divisors(n) ];
%Y A145915 Cf. A145832, A048098 (square-root smooth numbers), A145916.
%K A145915 nonn
%O A145915 1,1
%A A145915 _Klaus Brockhaus_, Oct 26 2008