cp's OEIS Frontend

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.

A174223 Add to 2n+1 the next three primes > 2n+1.

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%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