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A071923
a(n) is the prime p such that pi(n^2, (n+1)^2+1) = pi((n+1)^2, p) where pi(s,t) = pi(t) - pi(s) is the number of primes between s and t.
0
7, 13, 19, 37, 41, 67, 73, 101, 107, 149, 163, 193, 227, 239, 281, 337, 353, 397, 433, 479, 523, 577, 607, 677, 733, 769, 829, 907, 953, 1013, 1091, 1151, 1229, 1289, 1373, 1439, 1489, 1601, 1667, 1777, 1867, 1907, 2027, 2099, 2237, 2281, 2389, 2543, 2591
OFFSET
1,1
EXAMPLE
a(1)=7 because pi(1,4)=2 and pi(4,7)=2.
PROG
(PARI) pi(m, n)=local(i, pic); pic=0; forprime (i=m, n, pic++); pic;
for (x=1, 500, xc=0; px=pi(x^2, (x+1)^2); forprime (y=(x+1)^2, 100000, xc++; if (xc==px, print1(y, ", "); break)))
CROSSREFS
Sequence in context: A208720 A208776 A108295 * A344045 A048646 A152087
KEYWORD
nonn
AUTHOR
Jon Perry, Jun 14 2002
EXTENSIONS
Title clarified and offset corrected by Sean A. Irvine, Aug 21 2024
STATUS
approved