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 A121705 Triangle read by rows: 5^n expressed as the sum of two squares. 2
 0, 1, 1, 2, 0, 5, 3, 4, 2, 11, 5, 10, 0, 25, 7, 24, 15, 20, 10, 55, 25, 50, 38, 41, 0, 125, 35, 120, 44, 117, 75, 100, 29, 278, 50, 275, 125, 250, 190, 205, 0, 625, 175, 600, 220, 585, 336, 527, 375, 500, 145, 1390, 250, 1375, 625, 1250, 718, 1199, 950, 1025, 0, 3125 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS EXAMPLE 5^n expressed as the sum of two squares: 5^n = x^2 + y^2, 0 <= x < y. Number of solutions for n=0,1,...: a(n)=1,1,2,2,3,3,4,4,5,5,6,6,... Triangle of solutions for n=0,1,...: {x,y} {{0,1}}, {{1,2}}, {{0,5},{3,4}}, {{2,11},{5,10}}, {{0,25},{7,24},{15,20}}, {{10,55},{25,50},{38,41}}, {{0,125},{35,120},{44,117},{75,100}}, {{29,278},{50,275},{125,250},{190,205}}, {{0,625},{175,600},{220,585},{336,527},{375,500}}, {{145,1390},{250,1375},{625,1250},{718,1199},{950,1025}}, {{0,3125},{237,3116},{875,3000},{1100,2925},{1680,2635},{1875,2500}}, {{725,6950},{1250,6875},{2642,6469},{3125,6250},{3590,5995},{4750,5125}}, {{0,15625},{1185,15580},{4375,15000},{5500,14625},{8400,13175},{9375,12500},10296,11753}} CROSSREFS Cf. A004431, A006496, A024507, A120905. Sequence in context: A184854 A021491 A324654 * A071782 A328495 A297024 Adjacent sequences:  A121702 A121703 A121704 * A121706 A121707 A121708 KEYWORD nonn,tabf AUTHOR Zak Seidov, Sep 10 2006 STATUS approved

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Last modified April 16 18:53 EDT 2021. Contains 343050 sequences. (Running on oeis4.)