OFFSET
1,1
COMMENTS
From Mikk Heidemaa, Mar 23 2015: (Start)
a(2),...,a(24) all have a single representation (in positive integers) as the sum of two squares (e.g., a(24) = 416865370156^2 + 428846797599^2) and as the hypotenuse of a primitive Pythagorean triple (357686312646216567629137^2 = 10132838975618776700465^2 + 357542758042644694110888^2).
---
a^2 + b^2 + c^2 + d^2 + e^2 + f^2 = 357686312646216567629137^2;
a=304233682432674451033719; b=185074861663432734470527;
c=4189176178164916432878; d=33333333333333333333333; e=3333333; f=3.
---
a^2 + b^2 + c^2 + d^2 + e^2 + f^2 = 357686312646216567629137^3;
a=210197737649788368191109924028342434;
b=39738123500625252940689952285037741;
c=777777777777777777777777;
d=777777777777777777777777;
e=777777777777777777;
f=777777777777.
a=170350493188466620042802284807886346;
b=129394423538599186274382140531063939;
c=777777777777777777777777;
d=777777777777777777777777;
e=777777777777777777;
f=777777777777.
---
x^2 + y^2 = 357686312646216567629137^3;
x=144701758632763782416276428525674993;
y=157555096461604743754426503960480452;
x=149107037120999813337660002835835372;
y=153392629723324670471173010334042063.
(End)
LINKS
Mikk Heidemaa, Table of n, a(n) for n = 1..24
James Grime and Brady Haran, 357686312646216567629137, Numberphile video (2018).
Miguel A. Martin-Delgado, Chiral Prime Concatenations, arXiv:2009.12305 [math.NT], 2020.
FORMULA
a(n) = 357686312646216567629137 mod 10^n. - José de Jesús Camacho Medina, Dec 21 2016
EXAMPLE
.......................7
......................37
.....................137
....................9137
...................29137
..................629137
.................7629137
................67629137
...............567629137
..............6567629137
.............16567629137
............216567629137
...........6216567629137
..........46216567629137
.........646216567629137
........2646216567629137
.......12646216567629137
......312646216567629137
.....6312646216567629137
....86312646216567629137
...686312646216567629137
..7686312646216567629137
.57686312646216567629137
357686312646216567629137
------------------------
MATHEMATICA
Table[Mod[357686312646216567629137, 10^n] , {n, 1, 24}] (* José de Jesús Camacho Medina, Dec 21 2016 *)
CROSSREFS
KEYWORD
nonn,fini,full,base
AUTHOR
Larry Calmer (larry(AT)wri.com), Simon Plouffe
STATUS
approved