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 A375352 #11 Aug 17 2024 13:59:13
%S A375352 1,7,23,41,73,103,151,193,257,311,391,457,553,631,743,833,961,1063,
%T A375352 1207,1321,1481,1607,1783,1921,2113,2263,2471,2633,2857,3031,3271,
%U A375352 3457,3713,3911,4183,4393,4681,4903,5207,5441,5761,6007,6343,6601,6953,7223,7591,7873
%N A375352 Numbers k such that 14*k + 2 is a square.
%C A375352 a(11) = 391 is first composite number in this sequence.
%H A375352 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,2,-2,-1,1).
%F A375352 a(n) = (A113804(n)^2 - 2)/14. - _Amiram Eldar_, Aug 13 2024
%F A375352 a(n) = 2*A212965(n-1) - 1. - _Hugo Pfoertner_, Aug 13 2024
%F A375352 E.g.f.: ((2 + x + 7*x^2)*cosh(x) + (1 - x + 7*x^2)*sinh(x) - 2)/2. - _Stefano Spezia_, Aug 13 2024
%t A375352 ((Table[14*n + {4, 10}, {n, 0, 23}] // Flatten)^2 - 2)/14 (* _Amiram Eldar_, Aug 13 2024 *)
%o A375352 (Magma) [k: k in [0..8000] | IsSquare(14*k + 2)];
%Y A375352 Numbers k such that (m + (16-m)*k) is a square: A204221 (m = 1), this sequence (m = 2), A001082 (m = 4), A181433 (m = 5), A273367 (m = 6), A266956 (m = 7), A056220 (m = 8), A274978 (m = 9), A028872 (m = 12), A161532 (m = 14).
%Y A375352 Cf. A113804, A212965.
%K A375352 nonn,easy
%O A375352 1,2
%A A375352 _Juri-Stepan Gerasimov_, Aug 12 2024