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 A386526 #7 Jul 30 2025 16:16:14
%S A386526 2097152,13436928,46656000,1073741824,1360800000,12884901888,
%T A386526 1486016741376,330225942528000,358318080000000,670777794086400,
%U A386526 1290482565120000,64925062108545024,69918208819200000,137274424455168000,164341563462254592,277326388342554624,415989582513831936
%N A386526 Products m of primorials (i.e., m in A025487) such that both m-1 and m+1 are not squarefree.
%C A386526 Proper subset of A386527.
%H A386526 Michael De Vlieger, <a href="/A386526/b386526.txt">Table of n, a(n) for n = 1..164</a> (all terms less than A002110(21)).
%e A386526 Table of n, a(n), showing exponents of prime factors of a(n), and the prime decomposition of a(n)-1 and a(n)+1 for n = 1..6:
%e A386526 Exponents
%e A386526 n a(n) 2.3.5.7 a(n)-1 a(n)+1
%e A386526 -----------------------------------------------------------------------------
%e A386526 1 2097152 21 7^2, 127, 337 3^2, 43, 5419
%e A386526 2 13436928 11.8 7^2, 274223 11^2, 111049
%e A386526 3 46656000 9.6.3 13^2, 359, 769 7, 19^2, 37, 499
%e A386526 4 1073741824 30 3^2, 7, 11, 31, 151, 331 5^2, 13, 41, 61, 1321
%e A386526 5 1360800000 8.5.5.1 13^2, 107, 75253 11^2, 167, 67343
%e A386526 6 12884901888 32.1 11, 13^3, 563, 947 19^2, 35692249
%t A386526 (* Load function f from A025487, then: *)
%t A386526 Select[Union@ Flatten@ f[12], AllTrue[# + {-1, 1}, Not @* SquareFreeQ] &]
%Y A386526 Cf. A000079, A002110, A013929, A025487, A375197, A386527.
%K A386526 nonn
%O A386526 1,1
%A A386526 _Michael De Vlieger_, Jul 24 2025