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A101750 Number of primitive Pythagorean hypotenuses less than or equal to 10^n. 0
2, 29, 293, 2649, 23760, 215594 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primitive Pythagorean hypotenuses (A004431) are of the form m^2+n^2, m>n>0.

LINKS

Table of n, a(n) for n=1..6.

EXAMPLE

a(2)=29 because there are 29 primitive Pythagorean hypotenuses which are {5, 10, 13, 17, 20, 25, 26, 29, 34, 37, 40, 41, 45, 50, 52, 53, 58, 61, 65, 68, 73, 74, 80, 82, 85, 89, 90, 97, 100}

MATHEMATICA

hyp = Union[ Flatten[ Table[ m^2 + n^2, {n, 2, 100000}, {m, n - 1}]]]; Table[ Length[ Select[ hyp, #<=10^n &]], {n, 8}]

CROSSREFS

Cf. A004431.

Sequence in context: A124301 A276196 A077023 * A160952 A088615 A091716

Adjacent sequences:  A101747 A101748 A101749 * A101751 A101752 A101753

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Nov 09 2004

STATUS

approved

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Last modified October 15 13:27 EDT 2018. Contains 316236 sequences. (Running on oeis4.)