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 1-4 of 4 results.

A233270 a(n) = A233271(n) - A179016(n).

Original entry on oeis.org

0, 0, -1, 0, 0, 0, 1, 0, 0, 2, 1, 2, 0, 0, 3, 3, 4, 3, 4, 3, 3, 0, 0, 4, 4, 5, 4, 6, 5, 5, 3, 5, 5, 6, 4, 5, 4, 4, 0, 0, 5, 8, 9, 10, 13, 13, 15, 16, 17, 18, 18, 17, 17, 19, 19, 17, 17, 18, 18, 17, 16, 15, 13, 13, 10, 9, 8, 5, 0, 0, 6, 9, 14, 17, 18, 20, 22, 21
Offset: 0

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Author

Antti Karttunen, Dec 14 2013

Keywords

Comments

For all n>=2, a(1+A213710(n)) = n-2.
Except for a(2)=-1 (which seems to be the only negative term in the sequence), the sequences A218600 and A213710 give the positions of zeros.
Furthermore, each subrange [A213710(n)..A218600(n+1)] is palindromic. A233268 gives the middle points of those ranges, the sequence A234018 gives the values at those points, while A234019 gives the maximum term in that range in this sequence.

Examples

			This irregular table begins as:
0;
0;
-1;
0, 0;
0, 1, 0;
0, 2, 1, 2, 0;
0, 3, 3, 4, 3, 4, 3, 3, 0;
0, 4, 4, 5, 4, 6, 5, 5, 3, 5, 5, 6, 4, 5, 4, 4, 0;
...
After zero, each row n is A213709(n-1) elements long.
		

Crossrefs

Except for a(2)=-1 (which seems to be the only negative term in the sequence), the sequences A218600 and A213710 give the positions of zeros.

Programs

Formula

a(n) = A233271(n) - A179016(n).
a(A218602(n)) = a(n). [This is just a claim that each row is palindrome]

A233268 The middle point of row n in binary beanstalk related sequences A179016, A218602, A218616, A233270, A233271.

Original entry on oeis.org

1, 2, 3, 6, 10, 17, 30, 53, 95, 171, 310, 564, 1036, 1918, 3574, 6691, 12566, 23653, 44610, 84309, 159698, 303253, 577352, 1102121, 2109448, 4047967, 7787277, 15015347, 29011671, 56150867, 108825599, 211127246, 409886210, 796134319, 1546848744, 3006198333, 5843799964
Offset: 1

Views

Author

Antti Karttunen, Dec 29 2013

Keywords

Comments

a(n) points to the center of each palindromic row/subrange of A233270, and to the lower position nearest to the center, if the length of range is even.
For all n, A218602(a(n)) = a(n) + (1-A000035(A213709(n-1))).

Crossrefs

Formula

a(n) = floor((A213710(n-1) + A218600(n)) / 2).
a(n) = A218600(n-1) + ceiling((A213709(n-1)/2)).

A234020 Offsets from the middle point of each row of A233270 to the nearest point containing a maximum value of that range.

Original entry on oeis.org

0, 0, 0, 0, 1, 1, 3, 0, 5, 0, 0, 33, 72, 140, 267, 502, 954, 1771, 3355
Offset: 1

Views

Author

Antti Karttunen, Dec 29 2013

Keywords

Comments

Please see the graph of A233270. Iff a(n)=0, A234018(n) = A234019(n).
Seems to grow faster than A233274. Is the ratio a(n)/A233274(n) converging to some limit?

Crossrefs

Programs

  • Scheme
    (define (A234020 n) (let ((middle (A233268 n))) (let loop ((i middle) (m 0) (maxp middle)) (cond ((zero? (A233270 i)) (- middle maxp)) ((> (abs (A233270 i)) m) (loop (- i 1) (abs (A233270 i)) i)) (else (loop (- i 1) m maxp))))))

A234019 Maximum values occurring in each row of A233270: a(n) = A233270(A233268(n) - A234020(n)).

Original entry on oeis.org

0, -1, 0, 1, 2, 4, 6, 19, 38, 67, 127, 234, 419, 745, 1378, 2678, 5311, 10470, 20333
Offset: 1

Views

Author

Antti Karttunen, Dec 29 2013

Keywords

Comments

Please see the graph of A233270.

Crossrefs

Formula

a(n) = A233270(A233268(n) - A234020(n)).
Showing 1-4 of 4 results.