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A178838 Indices n such that the sums of the squares of the digits of Fibonacci(n) are prime. 0
8, 14, 15, 18, 22, 25, 27, 29, 39, 44, 45, 46, 47, 65, 68, 69, 90, 94, 100, 103, 104, 107, 113, 116, 124, 133, 135, 138, 157, 164, 165, 166, 167, 168, 172, 175, 177, 187, 188, 193, 207, 223, 226, 229, 233, 247, 257, 260, 263, 265, 266, 270, 273, 276, 295, 299 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

8 is in the sequence because Fibonacci(8)=21, and 2^2 + 1^2 = 5 prime ;

14 is in the sequence because Fibonacci(14)=377,and 3^2 + 7^2 + 7^2 = 107 prime.

MAPLE

with(combinat, fibonacci):nn:= 120: for n from 1 to 700 do:p:=fibonacci(n):l:=length(p):n0:=p:s:=0:for m from 1 to l do:q:=n0:u:=irem(q, 10):v:=iquo(q, 10):n0:=v :s:=s+u^2:od:if type(s, prime)=true then printf(`%d, `, n): else fi:od:

MATHEMATICA

Flatten[Position[Fibonacci[Range[300]], _?(PrimeQ[Total[ IntegerDigits[ #]^2]]&), {1}, Heads->False]] (* Harvey P. Dale, Aug 31 2014 *)

CROSSREFS

Cf. A000045

Sequence in context: A092537 A226799 A236295 * A219303 A082772 A103338

Adjacent sequences:  A178835 A178836 A178837 * A178839 A178840 A178841

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Jun 17 2010

STATUS

approved

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Last modified March 27 16:36 EDT 2017. Contains 284177 sequences.