

A106318


Bhaskara twins: n such that 2*n^2 = X^3 and 2*n^3 = Y^2.


7



2, 128, 1458, 8192, 31250, 93312, 235298, 524288, 1062882, 2000000, 3543122, 5971968, 9653618, 15059072, 22781250, 33554432, 48275138, 68024448, 94091762, 128000000, 171532242, 226759808, 296071778, 382205952, 488281250, 617831552
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OFFSET

1,1


REFERENCES

S. S. Gupta, 'Bhaskara Pairs' in 'Science Today' (subsequently renamed '2001'), January 1988, pp. 68, Times of India, Mumbai.


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Richard J. Mathar, Construction of Bhaskara Pairs, arXiv:1703.01677 [math.NT], 2017.
Index entries for linear recurrences with constant coefficients, signature (7,21,35,35,21,7,1).


FORMULA

a(n) = 2*n^6 = 2*A001014(n).
G.f.: 2*(1+x)*(1+56*x+246*x^2+56*x^3+x^4)/(1x)^7.  Colin Barker, Apr 18 2012


MATHEMATICA

LinearRecurrence[{7, 21, 35, 35, 21, 7, 1}, {2, 128, 1458, 8192, 31250, 93312, 235298}, 30] (* Harvey P. Dale, May 11 2017 *)


PROG

(PARI) a(n)=2*n^6 \\ Charles R Greathouse IV, Feb 09 2012
(Haskell)
a106318 = (* 2) . (^ 6)  Reinhard Zumkeller, May 27 2015


CROSSREFS

Cf. A106319, A106320, A106321, A106322.
Cf. A001014.
Sequence in context: A106319 A226403 A106320 * A202748 A322308 A277757
Adjacent sequences: A106315 A106316 A106317 * A106319 A106320 A106321


KEYWORD

nice,nonn,easy


AUTHOR

Lekraj Beedassy, Apr 29 2005


STATUS

approved



