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A214802
a(n+1) is the smallest integer m > a(n) such that all of sums (a(i))^2 + m^2, i=1..n are squarefree.
1
1, 2, 3, 5, 13, 17, 23, 37, 49, 53, 67, 83, 97, 101, 103, 113, 137, 149, 151, 163, 167, 173, 263, 317, 337, 347, 353, 383, 401, 433, 451, 487, 503, 551, 563, 601, 701, 751, 773, 947, 967, 977, 983, 1013, 1033, 1049, 1051, 1087, 1187, 1201, 1249, 1283, 1333
OFFSET
1,2
COMMENTS
All terms except for a(2)=2 are odd.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..1000
MATHEMATICA
s={1}; m=1; Do[f=0; Do[If[!SquareFreeQ[s[[i]]^2+p^2], f=1; Break[]], {i, m}]; If[f<1, AppendTo[s, p]; m++], {p, 2, 10^3}]; s
PROG
(PARI) v=List([1]); for(m=2, 1e3, for(j=1, #v, if(issquare(m^2+v[j]^2), next(2))); listput(v, m)); Vec(v) \\ Charles R Greathouse IV, Jul 30 2012
CROSSREFS
Sequence in context: A038983 A235635 A253645 * A262840 A215318 A186945
KEYWORD
nonn
AUTHOR
Zak Seidov, Jul 28 2012
STATUS
approved