OFFSET
0,2
COMMENTS
No terms after a(13) are smaller than 99000000. - John W. Layman, Jan 20 2004
LINKS
Donovan Johnson, Table of n, a(n) for n = 0..33 (terms < 10^12)
EXAMPLE
a(2) = 410 = 7^2+19^2 = 11^2+17^2;
a(3) = 2210 = 19^2+43^2 = 23^2+41^2 = 29^2+37^2;
a(4) = 10370 = 13^2+101^2 = 31^2+97^2 = 59^2+83^2 = 71^2+73^2;
a(5) = 202130 = 23^2+449^2 = 97^2+439^2 = 163^2+419^2 = 211^2+397^2 = 251^2+373^2;
a(6) = 229970 = 23^2+479^2 = 109^2+467^2 = 193^2+439^2 = 263^2+401^2 = 269^2+397^2 = 331^2+347^2;
a(7) = 197210 = 31^2+443^2 = 67^2+439^2 = 107^2+431^2 = 173^2+409^2 = 199^2+397^2 = 241^2+373^2 = 311^2+317^2;
a(8) = 81770 = 41^2+283^2 = 53^2+281^2 = 71^2+277^2 = 97^2+269^2 = 137^2+251^2 = 157^2+239^2 = 179^2+223^2 = 193^2+211^2.
MATHEMATICA
(* This program is not convenient for a large number of terms *) nMax = 14; piMax = 2500; tp = Table[{Prime[i]^2 + Prime[j]^2, i, j}, {i, 1, piMax}, {j, i+1, piMax}] // Flatten[#, 1]&; sp = tp[[All, 1]] // Tally // Sort[#, #1[[2]] > #2[[2]]& ]& // Split[#, #1[[2]] == #2[[2]]& ]&; ssp = (Sort /@ sp)[[All, 1]]; a[0] = 1; Do[a[ssp[[n, 2]]] = ssp[[n, 1]], {n, 1, Length[ssp]}]; Table[a[n], {n, 0, nMax}] (* Jean-François Alcover, Jun 19 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 23 2003
EXTENSIONS
More terms from John W. Layman, Jan 20 2004
a(14)-a(23) from Donovan Johnson, May 08 2010
STATUS
approved