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 A309238 #19 Feb 03 2023 01:32:44 %S A309238 315797,9634877 %N A309238 Non-prime-square numbers equal to the sum of squares of consecutive primes from the least prime factor to the largest prime factor. %C A309238 So-called 2-straddled numbers; 1-straddled numbers are in A055233. %C A309238 a(3) > 7*10^14, if it exists. - _Giovanni Resta_, Jul 18 2019 %H A309238 M. Kures, <a href="https://doi.org/10.7546/nntdm.2019.25.2.8-15">Straddled numbers: numbers equal to the sum of powers of consecutive primes from the least prime factor to the largest prime factor</a>, Notes on Number Theory and Discrete Mathematics, 2019, vol. 25, no. 2, pp. 8-15. ISSN: 1310-5132. %e A309238 9634877 = 7 * 41 * 59 * 569 = 7^2 + 11^2 + 13^2 + ... + 569^2. %o A309238 (PARI) isok(n) = if (isprimepower(n) != 2, if (n>1, my(f=factor(n)[,1], s=0); forprime(p=vecmin(f), vecmax(f), s+= p^2); s == n)); \\ _Michel Marcus_, Jul 18 2019 %Y A309238 Cf. A055233. %K A309238 nonn,more,bref %O A309238 1,1 %A A309238 _Miroslav Kures_, Jul 17 2019