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 1-3 of 3 results.

A245814 Permutation of natural numbers induced when A091204 is restricted to nonprime numbers: a(n) = 1+A091245(A091204(A018252(n))).

Original entry on oeis.org

1, 2, 4, 5, 3, 9, 8, 16, 6, 11, 7, 21, 22, 39, 18, 15, 29, 10, 34, 13, 24, 33, 76, 38, 14, 48, 42, 44, 46, 81, 20, 19, 37, 54, 32, 92, 60, 23, 63, 71, 25, 99, 28, 233, 30, 50, 98, 70, 157, 17, 79, 31, 89, 49, 101, 191, 86, 91, 12, 161, 94, 171, 193, 56, 167, 43, 143, 41, 353, 58, 75, 78, 113, 102, 68, 190, 125, 67, 119, 47, 130, 72, 146, 52, 27
Offset: 1

Views

Author

Antti Karttunen, Aug 16 2014

Keywords

Crossrefs

Inverse: A245813.
Related permutations: A091204, A245816, A245819.

Programs

Formula

a(n) = 1 + A091245(A091204(A018252(n))).
As a composition of related permutations:
a(n) = A245819(A245816(n)).

A245815 Permutation of natural numbers induced when A245821 is restricted to nonprime numbers: a(n) = A062298(A245821(A018252(n))).

Original entry on oeis.org

1, 2, 5, 3, 4, 7, 9, 59, 11, 6, 20, 125, 18, 25, 15, 10, 16, 26, 32, 31, 103, 8, 12, 35, 41, 50, 13, 39, 85, 64, 43, 164, 29, 38, 17, 66, 19, 24, 21, 45, 132, 37, 105, 139, 82, 33, 65, 27, 507, 52, 14, 180, 161, 96, 46, 22, 190, 141, 87, 1603, 80, 36, 143, 107, 54, 670, 34, 47, 23, 68, 177, 1337, 40
Offset: 1

Views

Author

Antti Karttunen, Aug 02 2014

Keywords

Comments

This permutation is induced when A245821 is restricted to nonprimes, A018252, the first column of A114537, but equally, when it is restricted to column 2 (A007821), column 3 (A049078), etc. of that square array, or alternatively, to the successive rows of A236542.
The sequence of fixed points f(n) begins as 1, 2, 15, 142, 548, 1694, 54681. A018252(f(n)) gives the nonprime terms of A245823.

Crossrefs

Inverse: A245816.
Related permutations: A245813, A245819, A245821.

Programs

Formula

a(n) = A062298(A245821(A018252(n))).
As a composition of related permutations:
a(n) = A245813(A245819(n)).
Also following holds for all n >= 1:

A245820 Permutation of natural numbers induced when A245704 is restricted to {1} and binary codes for polynomials reducible over GF(2): a(1) = 1, a(n) = A062298(A245704(A091242(n-1))).

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 9, 6, 10, 13, 16, 8, 11, 14, 17, 22, 26, 15, 19, 20, 23, 27, 34, 39, 25, 12, 29, 31, 35, 40, 50, 24, 56, 37, 21, 43, 46, 38, 51, 57, 70, 48, 36, 78, 53, 33, 61, 18, 65, 55, 71, 79, 95, 67, 52, 30, 106, 75, 49, 42, 85, 54, 28, 89, 77, 96, 107, 74, 126, 92, 73, 45, 141, 98, 101, 69, 59, 116, 76, 41, 120, 105
Offset: 1

Views

Author

Antti Karttunen, Aug 16 2014

Keywords

Crossrefs

Inverse: A245819.
Related permutations: A245704, A245813, A245816.

Programs

Formula

a(1) = 1, and for n > 1, a(n) = 1 + A245704(n-1).
a(1) = 1, and for n > 1, a(n) = A062298(A245704(A091242(n-1))). [Induced when A245704 is restricted to {1} and binary codes for polynomials reducible over GF(2)].
a(1) = 1, and for n > 1, a(n) = A036234(A245704(A014580(n-1))). [Induced also when A245703 is restricted to {1} and other binary codes for polynomials not reducible over GF(2)].
As a composition of related permutations:
a(n) = A245816(A245813(n)).
Showing 1-3 of 3 results.