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Search: id:A076170
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| A076170 |
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Triangular numbers whose largest proper divisor is also triangular. |
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+0
1
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| 1, 3, 6, 45, 210, 7140, 122265, 242556, 1702935, 8239770, 279909630, 4601330415, 9508687656, 64088265153, 323015470680, 10973017315470, 173166468725253, 372759573255306, 2411897769074475
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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No more terms < 10^16. - David Wasserman (wasserma(AT)spawar.navy.mil), Apr 05 2005
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PROGRAM
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(PARI) isTriang(n) = local(x); x = sqrtint(2*n); n == x*(x + 1)/2; i = 1; n = 1; while(1, i++; n += i; f = factor(n); if (isTriang(n/f[1, 1]), print(n))); (Wasserman)
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CROSSREFS
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Sequence in context: A133005 A009581 A088674 this_sequence A137775 A038050 A032322
Adjacent sequences: A076167 A076168 A076169 this_sequence A076171 A076172 A076173
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KEYWORD
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nonn
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AUTHOR
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Jason Earls (zevi_35711(AT)yahoo.com), Nov 01 2002
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EXTENSIONS
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More terms from David Wasserman (wasserma(AT)spawar.navy.mil), Apr 05 2005
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