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.

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A236859 The length of the initial ascent 123... in the n-th Catalan numeral, A239903(n).

Original entry on oeis.org

0, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2
Offset: 0

Views

Author

Antti Karttunen, Apr 18 2014

Keywords

Examples

			A239903(1) = 1, thus a(1) = 1.
A239903(2) = 10, thus a(2) = 1.
A239903(4) = 12, thus a(4) = 2.
A239903(39) = 1232, thus a(39) = 3.
A239903(58784) = 1234567899, thus a(58784) = 9.
Note that although the range of validity of A239903 is inherently limited by the decimal representation employed, it doesn't matter here: We have a(58785) = 10, as the corresponding 58785th Catalan String is [1,2,3,4,5,6,7,8,9,10], even though A239903 cannot represent that unambiguously.
		

Crossrefs

Programs

Formula

a(0) = 0, and for n>=1, a(n) = A126307(A081291(n))-1.
Each n occurs for the first time (as a record) at the position (C_{n+1})-1, so we have a(A001453(n+1)) = n for all n.

A082361 Permutation of natural numbers induced by the contraction of Catalan bijection signature-permutation A082351.

Original entry on oeis.org

0, 1, 4, 2, 3, 10, 11, 12, 5, 6, 13, 7, 8, 9, 28, 29, 30, 31, 32, 33, 34, 35, 14, 15, 36, 16, 17, 18, 37, 38, 39, 19, 20, 40, 21, 22, 23, 41, 24, 25, 26, 27, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 42, 43, 106, 44, 45, 46
Offset: 0

Views

Author

Antti Karttunen, Apr 17 2003

Keywords

Crossrefs

Inverse of A082362. Cf. also A082363-A082364.

Formula

a(n) = A082853(A082351(A081291(n))).

A082362 Permutation of natural numbers induced by the contraction of Catalan bijection signature-permutation A082352.

Original entry on oeis.org

0, 1, 3, 4, 2, 8, 9, 11, 12, 13, 5, 6, 7, 10, 22, 23, 25, 26, 27, 31, 32, 34, 35, 36, 38, 39, 40, 41, 14, 15, 16, 17, 18, 19, 20, 21, 24, 28, 29, 30, 33, 37, 64, 65, 67, 68, 69, 73, 74, 76, 77, 78, 80, 81, 82, 83, 92, 93, 95, 96, 97, 101, 102, 104, 105, 106, 108, 109, 110, 111
Offset: 0

Views

Author

Antti Karttunen, Apr 17 2003

Keywords

Crossrefs

Inverse of A082361. Cf. also A082363-A082364.

Formula

a(n) = A082853(A082352(A081291(n))).

A085193 Repeating part of A085192.

Original entry on oeis.org

2, 6, 2, 4, 18, 2, 6, 2, 4, 10, 2, 4, 8, 58, 2, 6, 2, 4, 18, 2, 6, 2, 4, 10, 2, 4, 8, 26, 2, 6, 2, 4, 10, 2, 4, 8, 18, 2, 4, 8, 16, 202, 2, 6, 2, 4, 18, 2, 6, 2, 4, 10, 2, 4, 8, 58, 2, 6, 2, 4, 18, 2, 6, 2, 4, 10, 2, 4, 8, 26, 2, 6, 2, 4, 10, 2, 4, 8, 18, 2, 4, 8, 16, 74, 2, 6, 2, 4, 18, 2, 6, 2, 4, 10
Offset: 0

Views

Author

Antti Karttunen, Jun 14 2003

Keywords

Crossrefs

Same sequence divided by 2: A085194. Cf. A085190.

Formula

a(n) = A085192(A081291(n+1)-1).
a(n) = 4*A085193(A085182(n+1)-1) + 2 - (2^A007001(n+1)) if A007001(n+2)==1, otherwise 2^A007001(n+1).

A220656 The positions of those permutations in A030298 where the first element is not fixed.

Original entry on oeis.org

3, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100
Offset: 1

Views

Author

Antti Karttunen, Dec 17 2012

Keywords

Comments

Correspondingly, gives the positions of those terms in A030299 whose first digit is not 1, as long as the decimal encoding system employed is valid.

Crossrefs

Complement: A220696. Cf. A081291.

Programs

Formula

a(n) = A003422(1+A084558(n)) + A000142(A084558(n)) + A212598(n).
a(n) = A220655(n)+1.

A244314 Nonnegative integers m such that the Semigreedy Catalan representation A244159(m) contains at least one zero.

Original entry on oeis.org

0, 2, 5, 6, 7, 14, 15, 16, 17, 18, 19, 20, 21, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157
Offset: 0

Views

Author

Antti Karttunen, Jun 25 2014

Keywords

Comments

Starting offset is zero because A244159(0) = 0 is a borderline case (either one zero, or no zeros if leading zeros are discarded).
From a(1)=2 onward the positions of zeros in A244233.
After zero consists of successive subsequences containing terms from A000108(k) to (A000108(k)+A014138(k-2)-1) computed from k >= 2 onward, as: [2], [5,6,7], [14 .. 21], [42 .. 63], [132 .. 195], [429 .. 624], [1430 .. 2054], [4862 .. 6916], etc.

Crossrefs

Programs

Formula

a(0) = 0, a(1) = 2, and for n >= 2, a(n) = n + A000108(1+A244317(n)) - A014143(A244317(n)-2) - 1.

A080336 Partial sums of A007001.

Original entry on oeis.org

0, 1, 3, 4, 6, 9, 10, 12, 13, 15, 18, 19, 21, 24, 28, 29, 31, 32, 34, 37, 38, 40, 41, 43, 46, 47, 49, 52, 56, 57, 59, 60, 62, 65, 66, 68, 71, 75, 76, 78, 81, 85, 90, 91, 93, 94, 96, 99, 100, 102, 103, 105, 108, 109, 111, 114, 118, 119, 121
Offset: 0

Views

Author

Benoit Cloitre, Mar 18 2003

Keywords

Crossrefs

The repeating subsequences in A085196 increase to this sequence. Difference between the position of (n+1)-th 1 in A007001 (= A085197(n)) and A007001(n+1). Also a(n) = A085196(A081291(n)).

A082327 Permutation of natural numbers induced by the contraction of Catalan bijection signature-permutation A082325.

Original entry on oeis.org

0, 1, 3, 2, 4, 8, 9, 7, 5, 6, 12, 10, 11, 13, 22, 23, 26, 25, 27, 21, 24, 19, 14, 15, 20, 17, 16, 18, 35, 36, 33, 28, 29, 34, 30, 31, 32, 40, 37, 38, 39, 41, 64, 65, 68, 67, 69, 77, 78, 76, 73, 74, 82, 80, 81, 83, 63, 66, 75, 72, 79, 61, 70, 56, 42, 43, 57, 45, 44, 46
Offset: 0

Views

Author

Antti Karttunen, Apr 17 2003

Keywords

Crossrefs

Inverse of A082328. a(n) = A072798(A082328(A072798(n))). Cf. also A082329-A082330.

Formula

a(n) = A082853(A082325(A081291(n))).

A082328 Permutation of natural numbers induced by the contraction of Catalan bijection signature-permutation A082326.

Original entry on oeis.org

0, 1, 3, 2, 4, 8, 9, 7, 5, 6, 11, 12, 10, 13, 22, 23, 26, 25, 27, 21, 24, 19, 14, 15, 20, 17, 16, 18, 31, 32, 34, 35, 36, 30, 33, 28, 29, 38, 39, 40, 37, 41, 64, 65, 68, 67, 69, 77, 78, 76, 73, 74, 81, 82, 80, 83, 63, 66, 75, 72, 79, 61, 70, 56, 42, 43, 57, 45, 44, 46
Offset: 0

Views

Author

Antti Karttunen, Apr 17 2003

Keywords

Crossrefs

Inverse of A082327. a(n) = A072798(A082327(A072798(n))). Cf. also A082329-A082330.

Formula

a(n) = A082853(A082326(A081291(n))).

A082329 Permutation of positive natural numbers: a(n) = A082327(n-1)+1.

Original entry on oeis.org

1, 2, 4, 3, 5, 9, 10, 8, 6, 7, 13, 11, 12, 14, 23, 24, 27, 26, 28, 22, 25, 20, 15, 16, 21, 18, 17, 19, 36, 37, 34, 29, 30, 35, 31, 32, 33, 41, 38, 39, 40, 42, 65, 66, 69, 68, 70, 78, 79, 77, 74, 75, 83, 81, 82, 84, 64, 67, 76, 73, 80, 62, 71, 57, 43, 44, 58, 46, 45, 47
Offset: 1

Views

Author

Antti Karttunen, Apr 17 2003

Keywords

Crossrefs

Inverse of A082330. a(n) = A082854(A082325(A081291(n-1))).
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