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.

A358002 Numbers k such that one of k-A001414(k) and k+A001414(k) is a prime and the other is the square of a prime.

Original entry on oeis.org

135, 936, 1431, 3510, 5005, 5106, 5278, 9471, 10648, 10659, 22126, 26724, 27420, 27840, 37014, 37149, 39321, 40311, 54730, 59031, 62830, 87186, 124914, 128616, 129411, 133494, 187705, 196078, 208285, 209451, 212695, 309885, 322191, 325465, 375513, 410515, 412476, 433041, 459844, 466620, 595833, 622083
Offset: 1

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Author

J. M. Bergot and Robert Israel, Oct 23 2022

Keywords

Comments

The Generalized Bunyakovsky conjecture implies that there are, for example, infinitely many primes q == 11 (mod 26) such that p = (q^2+9)/26 and 28*p+9 are prime, and then 27*p is in the sequence.

Examples

			a(4) = 3510 is a term because 3510 = 2*3^3*5*13 so A001414(3510) = 2+3*3+5+13 = 29 and 3510-29 = 3481 = 29^2 is the square of a prime, while 3510+29 = 3539 is prime.
		

Crossrefs

Programs

  • Maple
    filter:= proc(n) local t,s,x,y;
       s:= add(t[1]*t[2], t = ifactors(n)[2]);
       x:= s+n; y:= n-s;
       if issqr(x) then isprime(sqrt(x)) and isprime(y)
       else issqr(y) and isprime(sqrt(y)) and isprime(x)
       fi
    end proc:
    select(filter, [$1..10^6]);