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Search: id:A120960
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| A120960 |
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Pythagorean prime powers. |
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+0
3
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| 5, 13, 17, 25, 29, 37, 41, 53, 61, 73, 89, 97, 101, 109, 113, 125, 137, 149, 157, 169, 173, 181, 193, 197, 229, 233, 241, 257, 269, 277, 281, 289, 293, 313, 317, 337, 349, 353, 373, 389, 397, 401, 409, 421, 433, 449, 457, 461, 509, 521, 541, 557, 569, 577, 593
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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1 + sum of the indices of the first two numbers in A001844 that are divisible by n, if 1 + the sum of those indices equals n. - Mats Granvik (mgranvik(AT)abo.fi), Oct 16 2007
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LINKS
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Eric Weisstein's World of Mathematics, MathWorld, Centered Square Number.
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EXAMPLE
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A001844(1) = 5 is divisible by 5, A001844(3) = 25 is divisible by = 5 and 1+3+1=5, so 5 is a member.
A001844(2) = 13 is divisible by = 13, A001844(10) = 221 is divisible by = 13 and 2+10+1=13 so 13 is a member.
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PROGRAM
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(Excel cell formula) Generate the indices with: =if(mod(1+2*row()*(row()+1); 4*column()+1)=0; row(); ") Then sum the first two indices if it equals the column + 1. - Mats Granvik (mgranvik(AT)abo.fi), Oct 16 2007
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CROSSREFS
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Cf. A002144.
Cf. A001844, subsequence of A000961.
Sequence in context: A004613 A008846 A162597 this_sequence A094194 A088511 A089545
Adjacent sequences: A120957 A120958 A120959 this_sequence A120961 A120962 A120963
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KEYWORD
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nonn
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AUTHOR
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Lekraj Beedassy (blekraj(AT)yahoo.com), Jul 19 2006
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