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A083572
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Smaller of two consecutive star numbers (A000567) such that their sum is a square.
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1
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0, 1, 2296, 40833, 22847280, 395417121, 219458276136, 3797122504033, 2107246056196960, 36460001965365441, 20233777167801893976, 350088938217540957633, 194284726332034400465040, 3361553948612830233684961
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| The star numbers referred to here are those defined as the sum of the n-th square and four times the (n-1)st triangular number: 3n^2 - 2n.
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LINKS
| Charles R Greathouse IV, Table of n, a(n) for n = 1..503
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EXAMPLE
| a(2)=1 because
...
.*.
...
plus
..*...*...*...*
........*......
..*...........*
...*.........*.
..*...........*
........*......
..*...*...*...*
is
..*...*...*...*
........*......
..*...........*
...*....*....*.
..*...........*
........*......
..*...*...*...*
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PROG
| (PARI) list(lim)=my(x=0, y=1, v=List(), t); lim=sqrt(12*lim+4)/6+1/3; while(x<=lim, listput(v, x*(3*x-2)); t=49*x+20*y+8; y=120*x+49*y+20; x=t); x=1; y=3; while(x<=lim, listput(v, x*(3*x-2)); t=49*x+20*y+8; y=120*x+49*y+20; x=t); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 24 2011
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CROSSREFS
| Sequence in context: A163513 A123911 A126173 * A179699 A195652 A204102
Adjacent sequences: A083569 A083570 A083571 * A083573 A083574 A083575
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KEYWORD
| nonn
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AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), Jun 13 2003
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EXTENSIONS
| a(10)-a(12) from Donovan Johnson (donovan.johnson(AT)yahoo.com), May 24 2009
Offset corrected and a(13)-a(14) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Jul 24 2011
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