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User: Marc Kouyoumdjian

Marc Kouyoumdjian has authored 2 sequences.

A358490 Composite Fibonacci numbers whose sum of prime factors (with multiplicity) is a prime.

34, 75025, 196418, 701408733, 225851433717, 591286729879, 23416728348467685, 420196140727489673, 927372692193078999176, 16641027750620563662096, 114059301025943970552219, 1264937032042997393488322, 5358359254990966640871840, 2353412818241252672952597492098, 3807901929474025356630904134051

Offset: 1

Marc Kouyoumdjian, Nov 18 2022

nonn

			75025 is a term because it is a composite Fibonacci number whose sum of prime factors 5, 5 and 3001 is 3011, a prime number.

Shyam Sunder Gupta, Prime Curios! 34

Intersection of A000045 and A046363.
Intersection of A090206 and A100118.
Cf. A001414.

A352124 Fibonacci numbers k such that pi(k) is also a Fibonacci number.

Original entry on oeis.org

0, 1, 2, 3, 5, 21, 144

Offset: 1

Marc Kouyoumdjian, Mar 05 2022

No examples larger than pi(144) = 34 are known.

Next term is > Fibonacci(123), if it exists (checked using the b-file in A054782). - Amiram Eldar, Mar 05 2022

			21 is a term because 21 = Fibonacci(8) and pi(21) = 8 = Fibonacci(6).

G. L. Honaker, Jr., Prime Curios!.
Ron Knott, The Mathematical Magic of Fibonacci Numbers.

Cf. A000045, A000720, A054782.

Select[(f = Fibonacci[Join[{0}, Range[2, 20]]]), MemberQ[f, PrimePi[#]] &] (* Amiram Eldar, Mar 05 2022 *)

isfib(n) = my(k=n^2); k+=(k+1)<<2; issquare(k) || (n>0 && issquare(k-8));
lista(nn) = for (n=0, nn, if (n!=1, my(k=fibonacci(n)); if (isfib(primepi(k)), print1(k, ", ")))); \\ Michel Marcus, Mar 07 2022

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User: Marc Kouyoumdjian

A358490 Composite Fibonacci numbers whose sum of prime factors (with multiplicity) is a prime.

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A352124 Fibonacci numbers k such that pi(k) is also a Fibonacci number.

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