A088109 - OEIS

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A088109

a(1)=1, a(n)= least odd triangular number which is a proper multiple of a(n-1) with a multiplier different from the ones used earlier.

1, 3, 15, 105, 2415, 26565, 1567335, 2785154295, 6918860803558935, 24055444284403886996443725, 332872543972802173225078010738842685950725, 571002075998998180604720399522520480910497598676930064638396594614026468525

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..12.

EXAMPLE

a(2)/a(1) = 3, a(3)/a(2) = 5, a(4)/a(3) = 7, a(5)/a(4) = 23.

a(4) = 105 and not 45, = 3*15.

CROSSREFS

Cf. A088108.

Sequence in context: A048599 A129731 A269455 * A231634 A353587 A128276

Adjacent sequences: A088106 A088107 A088108 * A088110 A088111 A088112

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Sep 24 2003

EXTENSIONS

More terms from David Wasserman, Jul 20 2005

STATUS

approved