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 A174223 #14 Nov 26 2021 07:32:05 %S A174223 11,26,36,48,50,60,72,74,88,102,104,120,122,124,138,152,154,156,168, %T A174223 170,184,202,204,220,222,224,240,242,244,258,272,274,276,290,292,306, %U A174223 324,326,328,348,350,370,372,374,390,392,394,396,408,410,420,432,434,456,480,482,508,510,512,514,516,518,520,534,536,556,558,560,576,596,598,600,602,604 %N A174223 Add to 2n+1 the next three primes > 2n+1. %C A174223 Bisection of A174221. %H A174223 Michael De Vlieger, <a href="/A174223/b174223.txt">Table of n, a(n) for n = 0..10000</a> %t A174223 Array[Total@ Prepend[NextPrime[#, {1, 2, 3}], #] &[2 # + 1] &, 74, 0] (* _Michael De Vlieger_, Oct 25 2017 *) %o A174223 (PARI) A174223(n)=sum(c=1, 3, n=nextprime(n+1),n=2*n+1) \\ _M. F. Hasler_, Oct 25 2017 %o A174223 (Python) %o A174223 from sympy import nextprime %o A174223 def a(n): %o A174223 base = 2*n + 1 %o A174223 p1 = nextprime(base) %o A174223 p2 = nextprime(p1) %o A174223 p3 = nextprime(p2) %o A174223 return base + p1 + p2 + p3 %o A174223 print([a(n) for n in range(74)]) # _Michael S. Branicky_, Nov 26 2021 %Y A174223 Cf. A174221, A193230. %K A174223 nonn %O A174223 0,1 %A A174223 _N. J. A. Sloane_, Nov 26 2010