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.

A228195 Primes with the property that the sum of the cubes of their digits plus the prime equals another prime squared.

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%I A228195 #23 Oct 15 2023 16:47:29
%S A228195 17,2897,11471,15527,19949,26693,26783,72467,78041,142757,159209,
%T A228195 216791,350747,366917,672593,725891,775007,1187939,1529153,1659737,
%U A228195 2024093,2035097,2035349,2105231,2127761,2598929,2645933,2917799,3322439,3497993,3970643,4042697,4067513,4280051,4329257,4464017,5839397
%N A228195 Primes with the property that the sum of the cubes of their digits plus the prime equals another prime squared.
%H A228195 Charles R Greathouse IV, <a href="/A228195/b228195.txt">Table of n, a(n) for n = 1..10000</a>
%e A228195 17 is a term since (1^3 + 7^3) + 17 = 19^2.
%e A228195 2897 is a term since (2^3 + 8^3 + 9^3 + 7^3) + 2897 = 67^2.
%e A228195 11471 is a term since (1^3 + 1^3 + 4^3 + 7^3 + 1^3) + 11471 = 109^2.
%t A228195 Select[Prime[Range[403000]],PrimeQ[Sqrt[#+Total[IntegerDigits[#]^3]]]&] (* _Harvey P. Dale_, Oct 15 2023 *)
%o A228195 (PARI) is(n)=my(d=digits(n),k); issquare(sum(i=1,#d,d[i]^3)+n,&k) && isprime(k) && isprime(n) \\ _Charles R Greathouse IV_, Jun 16 2014
%o A228195 (PARI) searchdigit(n)=my(v=List(),N1=10^(n-1),N2=10^n,t=729*n,d,k,p2);forprime(p=sqrtint(N1)+1,sqrtint(N2+t),p2=p^2;forprime(q=max(N1,p2-t+2),min(N2,p2-2),d=digits(q);if(sum(i=1,#d,d[i]^3)+q==p2,listput(v,q))));Vec(v)
%o A228195 v=[];for(n=1,9,v=concat(v,searchdigit(n))); v \\ _Charles R Greathouse IV_, Jun 16 2014
%K A228195 nonn,base,less
%O A228195 1,1
%A A228195 _Will Gosnell_, Aug 15 2013
%E A228195 a(10)-a(37) from _Charles R Greathouse IV_, Jun 16 2014