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.

A247204 Fixed points of permutations A250552 and A250553.

Original entry on oeis.org

1, 2, 3, 4, 10, 45, 46, 47, 48, 49, 50, 71, 72, 73, 74, 75, 80, 90, 91, 92, 93, 185, 186, 187, 188, 189, 194, 195, 199, 205, 206, 207, 210, 211, 212, 213, 214, 217, 218, 219, 220, 221, 232, 233, 239, 288, 289, 290, 291, 292, 328, 329, 330, 336, 337, 338, 339
Offset: 1

Views

Author

Reinhard Zumkeller, Dec 10 2014

Keywords

Comments

A250552(a(n)) = A250553(a(n)) = a(n).

Links

Crossrefs

Cf. A250552, A250553.

Programs

  • Haskell
    a247204 n = a247204_list !! (n-1)
a247204_list = filter ((zipWith (==) [1..] a250552_list) !!) [1..]

A250553 Inverse permutation to A250552.

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 9, 13, 6, 8, 11, 15, 10, 12, 14, 17, 19, 16, 18, 21, 23, 25, 20, 22, 27, 29, 31, 33, 35, 26, 37, 28, 24, 30, 39, 32, 34, 41, 43, 36, 38, 45, 40, 42, 44, 46, 47, 48, 49, 50, 51, 55, 52, 53, 57, 54, 56, 59, 61, 58, 60, 63, 65, 62, 66, 64, 68
Offset: 1

Views

Author

Reinhard Zumkeller, Dec 10 2014

Keywords

Links

Crossrefs

Cf. A250552 (inverse), A247204 (fixed points).

Programs

  • Haskell
    import Data.List (elemIndex); import Data.Maybe (fromJust)
a250553 = (+ 1) . fromJust . (`elemIndex` a250552_list)

A247797 Lexicographically earliest permutation of prime numbers, such that adjacent terms have coprime sums of digits in decimal representation.

Original entry on oeis.org

2, 3, 5, 7, 11, 23, 13, 29, 17, 41, 31, 43, 19, 47, 37, 61, 53, 67, 59, 83, 71, 89, 73, 137, 79, 113, 97, 131, 101, 139, 103, 151, 107, 157, 109, 173, 127, 179, 149, 191, 163, 193, 167, 197, 181, 199, 211, 223, 227, 229, 233, 241, 251, 263, 239, 269, 257
Offset: 1

Views

Author

Reinhard Zumkeller, Nov 25 2014

Keywords

Comments

A049084(a(n)) defines a permutation of the positive integers, cf. A250552.

Links

Crossrefs

Cf. A000040, A007953, A007605, A049084, A250552, A119449, A119450.

Programs

  • Haskell
    import Data.List (delete)
a247797 n = a247797_list !! (n-1)
a247797_list = f 1 $ zip a000040_list a007605_list where
   f q' vws = g vws where
     g  ((p,q):pqs) = if gcd q q' == 1
                         then p : f q (delete (p,q) vws) else g pqs
Showing 1-3 of 3 results.

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

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