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A056893
Smallest prime with square excess of n.
5
2, 3, 7, 13, 41, 31, 23, 89, 73, 59, 47, 61, 113, 239, 79, 97, 593, 139, 163, 461, 277, 191, 167, 193, 281, 251, 223, 317, 353, 991, 431, 761, 433, 563, 359, 397, 521, 479, 439, 569, 617, 571, 619, 773, 829, 887, 947, 673, 1493, 1571, 727, 1013, 953, 1279
OFFSET
1,1
FORMULA
a(n) =n+A056894(n).
a(n) = min{p in A000040: A053186(p) = n}. - R. J. Mathar, Jul 28 2013
EXAMPLE
a(4)=13 since 13=3^2+4, while 2, 3, 5, 7 and 11 have square excesses of 1, 2, 1, 3 and 3 respectively.
MAPLE
A056893 := proc(n)
local p ;
p :=2 ;
while A053186(p) <> n do
p := nextprime(p) ;
end do:
return p ;
end proc: # R. J. Mathar, Jul 28 2013
PROG
(PARI) A056893(n)={
local(p=2) ;
while( A053186(p)!=n,
p=nextprime(p+1)
) ;
return(p)
} /* R. J. Mathar, Jul 28 2013 */
KEYWORD
nonn
AUTHOR
Henry Bottomley, Jul 05 2000
STATUS
approved