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Search: id:A162393
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| A162393 |
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Fibonacci numbers equal to a pronic number or an anagram of a pronic number. |
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+0
1
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| 2, 21, 6765, 10946, 2178309, 14930352, 102334155, 701408733, 1134903170, 4807526976, 20365011074, 32951280099, 225851433717, 1548008755920, 10610209857723, 72723460248141, 117669030460994, 498454011879264
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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Fibonacci(1) = A000045(3) = 2 equals the pronic number A002378(1).
a(2) = Fibonacci(8) = A000045(8) = 21 is an anagram of 12= A002378(3).
a(3) = A000045(20) = 6765 is an anagram of 7656= A002378(87).
a(4) = A000045(21) = 10946 is an anagram of 19460=A002378(139) and 96410 = A002378(310).
a(5) = A000045(32) = 2178309 is an anagram of 7308912 =A002378(2703), of 8017392 =A002378(2831) and of 9731280 = A002378(3119).
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MAPLE
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Digits := 200 ; digFreq := proc(n) dgs := convert(n, base, 10) ; c := [seq(0, j=0..9)] ; for d in dgs do c := subsop(d+1= op(d+1, c)+1, c) ; od: c; end:
isAna := proc(a, b) RETURN( digFreq(a) = digFreq(b)) ; end:
isA002378 := proc(n) k := floor(sqrt(n)) ; RETURN(k*(k+1) = n ) ; end:
A055642 := proc(n) max(1, ilog10(n)+1) ; end:
for n from 1 do f := combinat[fibonacci](n) ; fdgs := A055642(f) ; for k from floor(sqrt(10^(fdgs-1))) do p := k*(k+1) ; if A055642(p) > fdgs then break; fi; if isAna(p, f) then printf("%d, \n", f) ; break; fi; od; od: # R. J. Mathar, Aug 14 2009
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CROSSREFS
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Sequence in context: A022470 A080815 A114846 this_sequence A077526 A083764 A141236
Adjacent sequences: A162390 A162391 A162392 this_sequence A162394 A162395 A162396
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KEYWORD
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nonn,base
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AUTHOR
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Claudio L Meller (claudiomeller(AT)gmail.com), Jul 02 2009
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EXTENSIONS
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Six more terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 14 2009
a(13)-a(18) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Oct 11 2009
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