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 A372335 #8 Apr 28 2024 09:35:28 %S A372335 14,15,78,161,591,1214,1317,1318,1326,1407,1418,1438,1506,1509,1514, %T A372335 1527,1538,1618,1626,1646,1658,1703,1714,1718,1734,1739,1758,1814, %U A372335 1834,1838,1839,1857,1858,1934,1938,2307,2427,2509,2517,2534,2535,2715,2757,2758,2869,2958,3419,3439,3514,3523 %N A372335 For a positive number k, let L(k) denote the list consisting of k followed by the prime factors of k, with repetition, in nondecreasing order; sequence gives composite k such that the digits of L(k) alternate being larger than and then smaller than the previous digit. %C A372335 No term can end in 0 or 2; a number ending in 2 would mean the first prime factor is 2, which would disqualify the number, while a number ending in 0 would mean the first 3 distinct prime factors would have to be 2, 3, 5 or 2, 5, either of which would also disqualify the number. %H A372335 Scott R. Shannon, <a href="/A372335/b372335.txt">Table of n, a(n) for n = 1..10000</a> %e A372335 161 is a term as 161 = 7 * 23 which when concatenated give "161723", the digits of which alternate from being larger than and then smaller than the previous digit. %Y A372335 Cf. A372336, A372280, A372308, A372034, A372029, A056704. %K A372335 nonn,base %O A372335 1,1 %A A372335 _Scott R. Shannon_, Apr 28 2024