

A356051


a(n) is the index of the start of the first run of exactly n identical values in A356048.


0




OFFSET

1,1


COMMENTS

a(n) is the index k of the first of exactly n consecutive primes p such that the least primes q for which 2*q^2p^2 is prime are all equal.


LINKS



EXAMPLE

a(3) = 103 as A356048(103) = A356048(104) = A356048(105) = 809, while A356048(102) = 811 and A356048(106) = 823 are different. Thus for prime(103) = 563, prime(104) = 569 and prime(105) = 571 we have 809^2  2*563^2 = 20543, 809^2  2*569^2 = 6959 and 809^2  2*571^2 = 2399 all prime.


MAPLE

f:= proc(n) local q;
q:= floor(sqrt(2)*n);
do
q:= nextprime(q);
if isprime(q^22*n^2) then return q fi;
od
end proc;
R:= Vector(6): count:= 0:
p:= 2: v:= f(2): c:= 1:
for k from 2 while count < 6 do
p:= nextprime(p);
w:= f(p);
if w = v then c:= c+1
else
if R[c] = 0 then R[c]:= kc; count:= count+1 fi;
v:= w;
c:= 1;
fi
od:
convert(R, list);


CROSSREFS



KEYWORD

nonn,more


AUTHOR



STATUS

approved



