cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-5 of 5 results.

A050610 Sum_{i=0..y} (C(y,i) mod 2)*F(2i+x) = FL(y+x)*A050613(y), where A050613(y) = Product_{i=0..floor(log_2(y+1))} L(2^i)^bit(y,i).

Original entry on oeis.org

0, 1, 1, 1, 3, 3, 2, 4, 6, 12, 3, 7, 9, 21, 21, 5, 11, 15, 33, 35, 77, 8, 18, 24, 54, 56, 126, 168, 13, 29, 39, 87, 91, 203, 273, 609, 21, 47, 63, 141, 147, 329, 441, 987, 987, 34, 76, 102, 228, 238, 532, 714, 1596, 1598, 3572, 55, 123, 165, 369, 385, 861, 1155, 2583
Offset: 0

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Author

Antti Karttunen, Oct 24 1999

Keywords

Comments

Rows cut from column 2 onward form a subset of Wythoff array (A035513), where the terms of column 0 (A051656) give the positions of those rows in that array.

Crossrefs

Transpose of A050609. First row: A000045, second row: A000032, third row: A022086.

Programs

  • Maple
    a(n) = generic_bincoeff_fibsum_as_sum( (n-((trinv(n)*(trinv(n)-1))/2)),(((trinv(n)-1)*(((1/2)*trinv(n))+1))-n) );

A048757 Sum_{i=0..2n} (C(2n,i) mod 2)*Fibonacci(i+2) = Sum_{i=0..n} (C(n,i) mod 2)*Fibonacci(2i+2).

Original entry on oeis.org

1, 4, 9, 33, 56, 203, 441, 1596, 2585, 9353, 20304, 73461, 124033, 448756, 974169, 3524577, 5702888, 20633243, 44791065, 162055596, 273617239, 989956471, 2149017696, 7775219067, 12591974497, 45558191716, 98898651657
Offset: 0

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Author

Antti Karttunen, Jul 13 1999

Keywords

Comments

The history of 1-D CA Rule 90 starting from the seed pattern 1 interpreted as Zeckendorffian expansion.
Also, product of distinct terms of A001566 and appropriate Fibonacci or Lucas numbers: a(n) = FL(n+2)Product(L(2^i)^bit(n,i),i=0..) Here L(2^i) = A001566 and FL(n) = n-th Fibonacci number if n even, n-th Lucas number if n odd. bit(n,i) is the i-th digit (0 or 1) in the binary expansion of n, with the least significant digit being bit(n,0).

Examples

			1 = Fib(2) = 1;
101 = Fib(4) + Fib(2) = 3 + 1 = 4;
10001 = Fib(6) + Fib(2) = 8 + 1 = 9;
1010101 = Fib(8) + Fib(6) + Fib(4) + Fib(2) = 21 + 8 + 3 + 1 = 33; etc.
		

Crossrefs

a(n) = A022290(A038183(n)) = A022290(A048723(5, n)) = A003622(A051656(n)) = A075148(n, 2)*A050613(n). Third row of A050609, third column of A050610.
Cf. A054433.

Programs

  • Mathematica
    Table[Sum[Mod[Binomial[2n, i], 2] Fibonacci[i + 2], {i, 0, 2n}], {n, 0, 19}] (* Alonso del Arte, Apr 27 2014 *)

A050614 Products of distinct terms of A001566: a(n) = Product_{i=0..floor(log_2(n+1))} L(2^(i+1))^bit(n,i).

Original entry on oeis.org

1, 3, 7, 21, 47, 141, 329, 987, 2207, 6621, 15449, 46347, 103729, 311187, 726103, 2178309, 4870847, 14612541, 34095929, 102287787, 228929809, 686789427, 1602508663, 4807525989, 10749959329, 32249877987, 75249715303
Offset: 0

Views

Author

Antti Karttunen, Dec 02 1999

Keywords

Comments

Each subset a(0..(2^k)-1) gives all the divisors of F(2^(k+1)) up to k=4 (F_32) and after that a subset of such divisors. E.g., the terms a(0)-a(7) are the divisors of F_16 = 987 (A018760).

Crossrefs

Bisection of A075149 and A050613 (see there for the other Maple procedures), subset of A062877. Cf. also A050615.

Programs

  • Maple
    [seq(A050614(n),n=0..30)]; A050614 := n -> product('luc(2^(i+1))^bit_i(n,i)','i'=0..floor_log_2(n+1));
  • Mathematica
    Table[k = Floor[Log[2, n + 1]]; Product[j = 2^(i + 1); l = Fibonacci[j + 1] + Fibonacci[j - 1]; If[BitAnd[2^i, n] == 0, b = 0, b = 1]; l^b, {i, 0, k}], {n, 0, 200}] (* Robert Price, Feb 13 2017 *)

Formula

a(n) = Sum_{k=0..n} A127872(n,k)*Fibonacci(2*k+1), see A000045 and A001519. - Philippe Deléham, Aug 30 2007

A050609 Table T(n,k) = Sum_{i=0..2n} (C(2n,i) mod 2)*F(i+k) = Sum_{i=0..n} (C(n,i) mod 2)*F(2i+k).

Original entry on oeis.org

0, 1, 1, 3, 3, 1, 12, 6, 4, 2, 21, 21, 9, 7, 3, 77, 35, 33, 15, 11, 5, 168, 126, 56, 54, 24, 18, 8, 609, 273, 203, 91, 87, 39, 29, 13, 987, 987, 441, 329, 147, 141, 63, 47, 21, 3572, 1598, 1596, 714, 532, 238, 228, 102, 76, 34, 7755, 5781, 2585, 2583, 1155, 861, 385
Offset: 0

Views

Author

Antti Karttunen, Dec 02 1999

Keywords

Comments

Listed antidiagonalwise as T(0,0), T(1,0), T(0,1), T(2,0), T(1,1), T(0,2), ...

Crossrefs

Transpose of A050610. First row: A051656, second row: A050611, third row: A048757, fourth row: A050612. A050613 gives other Maple procedures. Cf. A025581, A002262.

Programs

  • Maple
    A050609_as_sum := proc(n,k) local i; RETURN(add(((binomial(n,i) mod 2)*fibonacci(k+2*i)),i=0..n)); end;
    A050609_as_product := (n,k) -> (`if`(1 = (n mod 2),luc(n+k),fibonacci(n+k)))*product('luc(2^i)^bit_i(n,i)','i'=1..floor_log_2(n+1)); # Produces same answers.
    [seq(A050609_as_sum(A025581(n), A002262(n)),n=0..119)];

Formula

Also a(n) = A075148(n, k)*A050613(n).

A050615 Products of distinct terms of Fibonacci(2^(i+2)): a(n) = Product_{i=0..floor(log_2(n+1))} F(2^(i+2))^bit(n,i).

Original entry on oeis.org

1, 3, 21, 63, 987, 2961, 20727, 62181, 2178309, 6534927, 45744489, 137233467, 2149990983, 6449972949, 45149810643, 135449431929, 10610209857723, 31830629573169, 222814407012183, 668443221036549, 10472277129572601
Offset: 0

Views

Author

Antti Karttunen, Dec 02 1999

Keywords

Crossrefs

Programs

  • Maple
    distinct_fib_products := n -> product('fib(2^(i+2))^bit_i(n,i)','i'=0..floor_log_2(n+1));
Showing 1-5 of 5 results.