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A249106 Numbers n that form a Pythagorean 6-tuple with their first four arithmetic derivatives. 3
19164, 129357, 14971875, 45316123, 434325391 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..5.

EXAMPLE

First four arithmetic derivatives of 19164 are 25564, 31848, 58412, 61916 and sqrt(19164^2 + 25564^2 + 31848^2 + 58412^2 + 61916^2) = 96336.

MAPLE

with(numtheory);

Dr:=proc(w) local x, p; x:=w*add(op(2, p)/op(1, p), p=ifactors(w)[2]); end:

P:=proc(q, h) local a, b, k, n; for n from 2 to q do a:=n; b:=n^2;

for k from 1 to h do a:=Dr(a); b:=b+a^2; od; if type(sqrt(b), integer) then print(n);

fi; od; end: P(10^9, 4);

CROSSREFS

Cf. A003415, A210503, A230543, A249105, A249107, A249110.

Sequence in context: A237554 A263024 A015302 * A184196 A210316 A323966

Adjacent sequences:  A249103 A249104 A249105 * A249107 A249108 A249109

KEYWORD

nonn,more

AUTHOR

Paolo P. Lava, Oct 21 2014

EXTENSIONS

a(4) from Ray Chandler, Dec 23 2016

a(5) from Ray Chandler, Jan 11 2017

STATUS

approved

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Last modified July 20 01:17 EDT 2019. Contains 325168 sequences. (Running on oeis4.)