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 A335774 #22 Sep 10 2023 08:43:15 %S A335774 14,21,28,35,56,63,98,112,147,154,175,182,189,196,224,231,238,245,266, %T A335774 273,308,322,357,364,385,392,399,406,434,441,448,455,476,483,518,532, %U A335774 567,574,595,602,609,616,644,651,658,665,686,693,728,742,777,784,805,812,819,826,854,861 %N A335774 Numbers k such that in prime factorization of k the second smallest factor is 7. %C A335774 Trivially, all terms are multiples of 7. Also terms are divisible by 2 or 3 or 5, and by any number of primes > 7. %H A335774 Ray Chandler, <a href="/A335774/b335774.txt">Table of n, a(n) for n = 1..1000</a> %H A335774 <a href="/index/Rec#order_15">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1). %e A335774 14 = 2*7, 28 = 2*2*7, 35 = 5*7, 56 = 2^3*7, 63 = 3*3*7, 147 = 3*7*7, 154 = 2*7*11. %t A335774 Select[Range[14, 1000], 1 < Length[fi = FactorInteger[#]] && 7 == fi[[2, 1]] &] %Y A335774 Cf. A008589 (multiples of 7). %Y A335774 Subsequence of A080671. %K A335774 nonn %O A335774 1,1 %A A335774 _Zak Seidov_, Jun 22 2020