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

1, 39, 100, 200, 305, 590, 652, 700, 1207, 1270, 1900, 2302, 2491, 4666, 6697, 9282, 10188, 10480, 11853, 12421, 13630, 13866, 14043, 14208, 14963, 15739, 15740, 18300, 18543, 18951, 20064, 21185, 21737, 23233, 24396, 24945, 25131, 25657

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..700

Example

a(2)=39, 39^4 = 2313441, (2! + 3! + 1! + 3! + 4! + 4! + 1!) = 64 = 8^2.

Maple

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

Mathematica

Select[Range[26000], IntegerQ[Sqrt[Total[IntegerDigits[#^4]!]]]&]  (* Harvey P. Dale, Feb 22 2011 *)

Crossrefs

Sequence in context: A062668 A158339 A211499 * A276401 A044226 A044607

Adjacent sequences: A126074 A126075 A126076 * A126078 A126079 A126080

Keyword

nonn,base

Author

Yalcin Aktar, Mar 02 2007

Extensions

More terms from Emeric Deutsch, Mar 06 2007

Name changed by Franklin T. Adams-Watters, Mar 29 2014

Status

approved