cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A126077 Numbers such that the sum of the factorials of the digits of the fourth power is a square.

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%I A126077 #17 Jan 27 2019 21:07:48
%S A126077 1,39,100,200,305,590,652,700,1207,1270,1900,2302,2491,4666,6697,9282,
%T A126077 10188,10480,11853,12421,13630,13866,14043,14208,14963,15739,15740,
%U A126077 18300,18543,18951,20064,21185,21737,23233,24396,24945,25131,25657
%N A126077 Numbers such that the sum of the factorials of the digits of the fourth power is a square.
%H A126077 Vincenzo Librandi, <a href="/A126077/b126077.txt">Table of n, a(n) for n = 1..700</a>
%e A126077 a(2)=39, 39^4 = 2313441, (2! + 3! + 1! + 3! + 4! + 4! + 1!) = 64 = 8^2.
%p A126077 a:=proc(n) local nn: nn:=convert(n^4,base,10): if type(sqrt(add(nn[j]!,j=1..nops(nn))),integer)=true then n else fi end: seq(a(n),n=1..32000); # _Emeric Deutsch_, Mar 06 2007
%t A126077 Select[Range[26000],IntegerQ[Sqrt[Total[IntegerDigits[#^4]!]]]&]  (* _Harvey P. Dale_, Feb 22 2011 *)
%K A126077 nonn,base
%O A126077 1,2
%A A126077 _Yalcin Aktar_, Mar 02 2007
%E A126077 More terms from _Emeric Deutsch_, Mar 06 2007
%E A126077 Name changed by _Franklin T. Adams-Watters_, Mar 29 2014