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.

A277695 Permutation of natural numbers: a(1) = 1; for n > 1, if A277815(n) = 0, a(n) = 2*a(A277814(n)-1), otherwise a(n) = 1 + 2*a(A277815(n)).

Original entry on oeis.org

1, 2, 4, 8, 3, 16, 6, 32, 12, 5, 13, 64, 7, 24, 10, 26, 128, 14, 27, 17, 25, 49, 48, 20, 257, 11, 21, 52, 15, 256, 28, 54, 34, 50, 55, 98, 515, 99, 9, 65, 31, 29, 97, 105, 51, 96, 40, 514, 22, 101, 43, 35, 1031, 513, 81, 42, 69, 23, 57, 104, 63, 30, 512, 56, 108, 68, 111, 100, 139, 199, 163, 110, 196, 203, 19, 211, 2063, 33, 195, 53, 1030, 47
Offset: 1

Views

Author

Antti Karttunen, Nov 06 2016

Keywords

Links

Crossrefs

Inverse: A277696.
Cf. A264977, A277710, A277814, A277815, A277816, A277817.

Formula

a(1) = 1; for n > 1, if A277815(n) = 0 [when n is in A277817], a(n) = 2*a(A277814(n)-1), otherwise a(n) = 1 + 2*a(A277815(n)).
a(1) = 1, a(A277817(1+n)) = 2*a(n), a(A277816(n)) = 1 + 2*a(n). [Implicit form.]

A277884 a(n) = A277814(A277826(n)).

Original entry on oeis.org

0, 1, 2, 3, 4, 1, 5, 6, 7, 8, 2, 6, 9, 1, 10, 11, 12, 13, 14, 6, 4, 8, 10, 15, 16, 13, 2, 11, 17, 1, 18, 19, 20, 21, 22, 6, 23, 13, 10, 3, 7, 1, 14, 15, 17, 8, 24, 25, 26, 27, 22, 11, 4, 13, 18, 25, 28, 21, 2, 19, 29, 1, 30, 31, 32, 33, 34, 6, 35, 21, 10, 25, 36, 37, 22, 3, 17, 13, 5, 15, 12, 38, 2, 15, 23, 1, 24, 39, 28, 37, 14, 25, 40, 8, 41
Offset: 0

Views

Author

Antti Karttunen, Nov 06 2016

Keywords

Links

Crossrefs

Cf. A264977, A277814.
Left inverse of A277817.
Cf. A277701, A277712, A277713, A277715 (positions of 1, 2, 3 and 8 in this sequence).
Cf. A277824, A277826 and their scatter-plots.

Programs

Formula

a(n) = A277814(A277826(n)).
Other identities. For all n >= 0:
a(A277817(n)) = n.

A277816 a(n) = the least k > n for which A264977(k) = A264977(n), or 0 if no such k exists.

Original entry on oeis.org

0, 5, 10, 39, 20, 13, 78, 11, 40, 21, 26, 19, 156, 29, 22, 27, 80, 25, 42, 35, 52, 45, 38, 43, 312, 37, 58, 51, 44, 41, 54, 59, 160, 57, 50, 67, 84, 53, 70, 75, 104, 61, 90, 79, 76, 93, 86, 55, 624, 101, 74, 99, 116, 77, 102, 71, 88, 69, 82, 115, 108, 85, 118, 123, 320, 121, 114, 131, 100, 117, 134, 91, 168, 89, 106, 147, 140, 109, 150, 83, 208, 105
Offset: 0

Views

Author

Antti Karttunen, Nov 06 2016

Keywords

Links

Crossrefs

Cf. A264977, A277710, A277814, A277816, A277826, A277696.
Cf. A277815 (a left inverse).
Cf. A277701, A277712, A277713, A277715 (iterates of this sequence starting from 1, 2, 3 and 9 respectively).

Programs

  • Scheme
    (define (A277816 n) (if (zero? n) n (let ((v (A264977 n))) (let loop ((k (+ 1 n))) (if (= v (A264977 k)) k (loop (+ 1 k)))))))

Formula

For all n >= 0, A277815(a(n)) = n.

A277815 a(n) = the largest k < n for which A264977(k) = A264977(n), or 0 if no such k exists.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 7, 0, 5, 0, 0, 0, 0, 0, 11, 4, 9, 14, 0, 0, 17, 10, 15, 0, 13, 0, 0, 0, 0, 0, 19, 0, 25, 22, 3, 8, 29, 18, 23, 28, 21, 0, 0, 0, 0, 34, 27, 20, 37, 30, 47, 0, 33, 26, 31, 0, 41, 0, 0, 0, 0, 0, 35, 0, 57, 38, 55, 0, 0, 50, 39, 44, 53, 6, 43, 16, 0, 58, 79, 36, 61, 46, 0, 56, 73, 42, 71, 0, 45, 0, 0, 0, 0, 0, 51
Offset: 0

Views

Author

Antti Karttunen, Nov 06 2016

Keywords

Links

Crossrefs

Cf. A264977, A277695, A277814, A277817 (the positions of zeros).
Left inverse of A277816.

Programs

  • Scheme
    (define (A277815 n) (if (zero? n) n (let ((v (A264977 n))) (let loop ((k (- n 1))) (cond ((zero? k) 0) ((= v (A264977 k)) k) (else (loop (- k 1))))))))

Formula

For all n >= 0, a(A277816(n)) = n.
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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