

A097579


Numbers n such that n and 2*n1 are triangular numbers.


0



1, 28, 946, 32131, 1091503, 37078966, 1259593336, 42789094453, 1453569618061, 49378577919616, 1677418079648878, 56982836130142231, 1935739010345186971, 65758143515606214778, 2233841140520266115476, 75884840634173441711401
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..16.


FORMULA

G.f.: x*(17*x+x^2)/((1x)*(134*x+x^2)).


MATHEMATICA

CoefficientList[ Series[x*(1  7*x + x^2)/((1  x)*(1  34*x + x^2)), {x, 0, 16}], x] (* Robert G. Wilson v, Sep 01 2004 *)


CROSSREFS

Cf. A075528, A124174.
Sequence in context: A129461 A239336 A203135 * A091549 A034904 A189995
Adjacent sequences: A097576 A097577 A097578 * A097580 A097581 A097582


KEYWORD

easy,nonn


AUTHOR

Vladeta Jovovic, Aug 29 2004


EXTENSIONS

More terms from Robert G. Wilson v, Sep 01 2004


STATUS

approved



