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A360932 Primes of the form H(m,k) = F(k+1)*F(m-k+2) - F(k)*F(m-k+1), where F(m) is the m-th Fibonacci number and m >= 0, 0 <= k <= m. 1
2, 3, 5, 7, 11, 13, 23, 29, 37, 41, 47, 89, 97, 103, 107, 157, 167, 173, 199, 233, 443, 521, 733, 1597, 1741, 1867, 1871, 1877, 2207, 3037, 3571, 7841, 7919, 7951, 9349, 11933, 12823, 28657, 33503, 50549, 54277, 54287, 54293, 54319, 54497, 55717, 142099 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
This sequence appears in the triangle A108038 in this order (reading by rows): 3, 2, 7, 5, 11, 13, 29, 23, 47, 37, 41, 97, 107, 103, 89, 199, 157, 173, 167.
Are there infinitely many primes of the form H(m,k)?
This sequence appears within the determinant Hosoya triangle.
LINKS
Hsin-Yun Ching, Rigoberto Florez, F. Luca, Antara Mukherjee, and J. C. Saunders, Primes and composites in the determinant Hosoya triangle, Fibonacci Quarterly, 2023.
FORMULA
Intersection of A000040 and A108038.
EXAMPLE
29 is a term because it is prime and A108038(8,2) = H(8,2) = 29. Also A108038(8,7) = H(8,7) = 29.
MAPLE
Res:= {}:
M:= 50: # for terms <= F(M)
fmax:= combinat:-fibonacci(M):
T[1]:= [1, 1]:
T[2]:= [1, 3, 1]:
for i from 3 to M do
t1:= [op(T[i-1][1..i-1] + T[i-2][1..i-1]), T[i-1][i], 0];
t2:= ListTools:-Reverse(t1);
T[i]:= zip(max, t1, t2);
Res:= Res union convert(select(t -> t <= fmax and isprime(t), T[i][1..ceil((i+1)/2)]), set)
od:
sort(convert(Res, list)); # Robert Israel, Mar 14 2024
MATHEMATICA
H[r_, k_] := Det[{{Fibonacci[r-k+2], Fibonacci[r-k+1]}, {Fibonacci[k], Fibonacci[k+1]}}]; DeterminantPrimes[t_, m_] := Table[If[PrimeQ[H[r, k]], H[r, k], Unevaluated[Sequence[]]], {r, t, m}, {k, 1, Ceiling[r/2]}]; ListOfPrimes[t_, m_]:= Sort[DeleteDuplicates[Flatten[DeterminantPrimes[t, m]]]]; ListOfPrimes[2, 100]
CROSSREFS
Cf. A000040, A000045, A005478 (subsequence), A108038, A153892, A067331.
Sequence in context: A350179 A229289 A087634 * A291691 A178576 A360147
KEYWORD
nonn
AUTHOR
Rigoberto Florez, Feb 25 2023
STATUS
approved

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Last modified September 1 13:22 EDT 2024. Contains 375591 sequences. (Running on oeis4.)