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 1-7 of 7 results.

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 *)

A050613 Products of distinct terms of 1 and rest from A001566: a(n) = Product_{i=0..floor(log_2(n+1))} L(2^i)^bit(n,i).

Original entry on oeis.org

1, 1, 3, 3, 7, 7, 21, 21, 47, 47, 141, 141, 329, 329, 987, 987, 2207, 2207, 6621, 6621, 15449, 15449, 46347, 46347, 103729, 103729, 311187, 311187, 726103, 726103, 2178309, 2178309, 4870847, 4870847, 14612541, 14612541, 34095929, 34095929
Offset: 0

Views

Author

Antti Karttunen, Dec 02 1999

Keywords

Comments

Used to produce the rows of A050609.
Also Sum(((C(2((n+((n+1) mod 2)) mod (2^floor(log_2(n)))),i) mod 2)*F(n+((n+1) mod 2)-i)),i=0..2((n+((n+1) mod 2)) mod (2^floor(log_2(n))))) or Sum(((C(2((n-(n mod 2)) mod (2^floor(log_2(n)))),i) mod 2)*L(n-(n mod 2)-i)),i=0..2((n-(n mod 2)) mod (2^floor(log_2(n))))) for all n > 1. Here F(n) and L(n) are n-th Fibonacci (A000045) and Lucas (A000032) numbers respectively.

Crossrefs

Bisection: A050614.

Programs

  • Maple
    with(combinat); A050613 := n -> product('luc(2^i)^bit_i(n,i)','i'=0..floor_log_2(n+1));
    luc := n -> (fibonacci(n-1)+fibonacci(n+1));
    bit_i := (n,i) -> `mod`(floor(n/(2^i)),2);
    floor_log_2 := proc(n) local nn,i; nn := n; for i from -1 to n do if(0 = nn) then RETURN(i); fi; nn := floor(nn/2); od; end;

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

Views

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) );

A051656 Sum_{i=0..n} (C(n,i) mod 2)*Fibonacci(2*i).

Original entry on oeis.org

0, 1, 3, 12, 21, 77, 168, 609, 987, 3572, 7755, 28059, 47376, 171409, 372099, 1346268, 2178309, 7881197, 17108664, 61899729, 104512485, 378129724, 820851717, 2969869413, 4809706272, 17401680769, 37775923491, 136674575148
Offset: 0

Views

Author

Antti Karttunen, Nov 30 1999

Keywords

Comments

Positions in the first column (A003622) of Wythoff array of the terms which have their Zeckendorf Expansion patterned as row[2n+1] in Pascal's Triangle computed modulo 2 (A047999)

References

  • Proof in preparation, to be published (see A048757).

Crossrefs

Cf. A048757, A047999, A035513, A038183, A051256. First row of A050609, First column of A050610.
a(n) = A019586[A048757[n]]. A048757[n] = SS(Athis_sequence[n])+1, where SSx means the second Fibonacci Successor of x (= x's Z.E. shifted left twice).
Cf. A001906.

Programs

  • Haskell
    a051656 = sum . zipWith (*) a001906_list . a047999_row
    -- Reinhard Zumkeller, Feb 27 2011
    
  • Mathematica
    Table[Sum[Mod[Binomial[n,i],2]Fibonacci[2i],{i,0,n}],{n,0,30}] (* Harvey P. Dale, Oct 30 2011 *)
  • PARI
    a(n)=sum(i=0,n,if(!bitand(i,n-i),fibonacci(2*i))) \\ Charles R Greathouse IV, Jan 04 2013

Formula

a(n) = sum_{i=0..n} (C(2n, 2i) mod 2)*F(2*i) = FL(n)product_{i=0..inf} L(2^i)^bit(n, i) where L is n-th Lucas number (A000032) and FL is defined as in A048757: FL(n) = n-th fibonacci number if n even, n-th Lucas number if n odd.

A075148 Table E(n,k) (listed antidiagonalwise as E(0,0), E(1,0), E(0,1), E(2,0), E(1,1), E(0,2), ...) where E(n,k) is F(n+k) for all even n and L(n+k) for all odd n. F(n) and L(n) are the n-th Fibonacci (A000045) and Lucas (A000032) numbers respectively.

Original entry on oeis.org

0, 1, 1, 1, 3, 1, 4, 2, 4, 2, 3, 7, 3, 7, 3, 11, 5, 11, 5, 11, 5, 8, 18, 8, 18, 8, 18, 8, 29, 13, 29, 13, 29, 13, 29, 13, 21, 47, 21, 47, 21, 47, 21, 47, 21, 76, 34, 76, 34, 76, 34, 76, 34, 76, 34, 55, 123, 55, 123, 55, 123, 55, 123, 55, 123, 55, 199, 89, 199, 89, 199, 89, 199
Offset: 0

Views

Author

Antti Karttunen, Sep 05 2002

Keywords

Crossrefs

Used to construct A050609 & A048757. Cf. A025581, A002262.

Programs

  • Maple
    with(combinat); [seq(A075148(A025581(n), A002262(n)),n=0..119)]; A075148 := (n,k) -> (fibonacci(n+k-(n mod 2))+fibonacci(n+k+(n mod 2)))/(2-(n mod 2));

Formula

E(n, k) = (fibonacci(n+k-(n mod 2))+fibonacci(n+k+(n mod 2)))/(2-(n mod 2))

A050611 Sum_{i=0..n} (C(n,i) mod 2)*Fibonacci(2i+1) = FL(n+1)Product(L(2^i)^bit(n,i),i=0..).

Original entry on oeis.org

1, 3, 6, 21, 35, 126, 273, 987, 1598, 5781, 12549, 45402, 76657, 277347, 602070, 2178309, 3524579, 12752046, 27682401, 100155867, 169104754, 611826747, 1328165979, 4805349654, 7782268225, 28156510947, 61122728166, 221144107989
Offset: 0

Views

Author

Antti Karttunen, Oct 24 1999

Keywords

Crossrefs

Second row of A050609, second column of A050610.

A050612 Sum_{i=0..n} (C(n,i) mod 2)*Fibonacci(2i+3) = FL(n+3)Product(L(2^i)^bit(n,i),i=0..).

Original entry on oeis.org

2, 7, 15, 54, 91, 329, 714, 2583, 4183, 15134, 32853, 118863, 200690, 726103, 1576239, 5702886, 9227467, 33385289, 72473466, 262211463, 442721993, 1601783218, 3477183675, 12580568721, 20374242722, 73714702663
Offset: 0

Views

Author

Antti Karttunen, Oct 24 1999

Keywords

Crossrefs

Fourth row of A050609, fourth column of A050610.
Showing 1-7 of 7 results.