A177887 - OEIS

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A177887

The areas of Pythagorean triangles divided by 6.

1, 4, 5, 9, 10, 14, 16, 20, 25, 30, 35, 36, 40, 45, 49, 55, 56, 64, 80, 81, 84, 90, 91, 100, 105, 120, 121, 125, 126, 140, 144, 154, 160, 165, 169, 180, 196, 204, 220, 224, 225, 231, 245, 250, 256, 260, 270, 285, 286, 289, 315, 320, 324, 336, 350, 360, 361, 364, 385, 390

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Number of terms less than 10^k: 4, 23, 109, 462, 1861, 7255, 27042, 95703, 314534, ..., .

This is A009112/6. - T. D. Noe, Oct 08 2013

Same as A256418/24, i.e., congrua/24. - Jonathan Sondow, Nov 07 2017

REFERENCES

Albert H. Beiler, Recreations in the Theory of Numbers, The Queen of Mathematics Entertains, 2nd Ed., Chpt. XIV, "The Eternal Triangle", pp. 104-134, Dover Publ., NY, 1964.

LINKS

Table of n, a(n) for n=1..60.

FORMULA

A009112(n)/6.

MATHEMATICA

(* First run the program given for A009112 *) Union[t/6]

CROSSREFS

Cf. A009112, A256418.

Sequence in context: A001983 A143575 A047208 * A032381 A191888 A050036

Adjacent sequences: A177884 A177885 A177886 * A177888 A177889 A177890

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Dec 14 2010

STATUS

approved