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A075634
Final terms of groups in A075631.
5
1, 2, 5, 18, 98, 306, 9378, 1726173, 13347339101, 321699559882750173, 4716070968330003553938242926173, 23987291841663781653328392594255840802707701158676395298
OFFSET
1,2
FORMULA
a(n) = A075633(n+1) - 1. Also, a(n) = (sqrt(8*(A075631(1) + A075631(2) + ... + A075631(n)) + 1) - 1) / 2. [From Max Alekseyev, May 08 2009]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 30 2002
EXTENSIONS
More terms from Jonathan Cross (jcross(AT)juggler.net), May 08 2004
One more term from Max Alekseyev, May 08 2009
STATUS
approved