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 A342280 #15 Mar 24 2021 15:44:11 %S A342280 3,10,17,23,30,37,44,51,58,64,71,78,85,92,99,105,112,119,126,133,139, %T A342280 146,153,160,167,174,180,187,194,201,208,215,221,228,235,242,249,256, %U A342280 262,269,276,283,290,297,303,310,317,324,331,338,344,351,358,365,372 %N A342280 a(n) = A001952(2*n+1). %H A342280 N. J. A. Sloane, <a href="/A115004/a115004.txt">Families of Essentially Identical Sequences</a>, Mar 24 2021 (Includes this sequence) %o A342280 (Python) %o A342280 from sympy import integer_nthroot %o A342280 def A342280(n): return 4*n+2+integer_nthroot(8*n*(n+1)+2,2)[0] # _Chai Wah Wu_, Mar 16 2021 %Y A342280 Bisection of A001952. %Y A342280 Cf. A187393. %K A342280 nonn %O A342280 0,1 %A A342280 _N. J. A. Sloane_, Mar 16 2021