cp's OEIS Frontend

A249107 Numbers that form a Pythagorean 7-tuple with their first five arithmetic derivatives.

%I A249107 #30 Feb 18 2021 00:19:27
%S A249107 4031,10823,416959,496939,1354980,9146115,38949392,44472866,262908396,
%T A249107 380264131
%N A249107 Numbers that form a Pythagorean 7-tuple with their first five arithmetic derivatives.
%C A249107 If we consider Pythagorean 8-tuple and 9-tuple there are no terms up to n = 10^8.
%e A249107 First five arithmetic derivatives of 4031 are 168, 332, 336, 832, 2560 and sqrt(4031^2 + 168^2 + 332^2 + 336^2 + 832^2 + 2560^2) = 4873.
%p A249107 with(numtheory);
%p A249107 Dr:=proc(w) local x,p; x:=w*add(op(2,p)/op(1,p),p=ifactors(w)[2]); end:
%p A249107 P:=proc(q,h) local a,b,k,n; for n from 2 to q do a:=n; b:=n^2;
%p A249107 for k from 1 to h do a:=Dr(a); b:=b+a^2; od; if type(sqrt(b),integer) then print(n);
%p A249107 fi; od; end: P(10^9,5);
%Y A249107 Cf. A003415, A210503, A230543, A249105, A249106, A249110.
%K A249107 nonn,more
%O A249107 1,1
%A A249107 _Paolo P. Lava_, Oct 21 2014
%E A249107 a(5)-a(6) from _Ray Chandler_, Dec 22 2016
%E A249107 a(7)-a(8) from _Ray Chandler_, Dec 23 2016
%E A249107 a(9) from _Ray Chandler_, Jan 02 2017
%E A249107 a(10) from _Ray Chandler_, Jan 08 2017