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.

A218533 Numerators of the ratios of consecutive terms in A176352.

Original entry on oeis.org

1, 1, 2, 1, 3, 1, 4, 1, 2, 5, 3, 3, 2, 1, 5, 5, 6, 1, 7, 2, 4, 3, 7, 1, 3, 4, 7, 5, 9, 1, 8, 6, 2, 5, 10, 1, 9, 3, 8, 1, 4, 7, 5, 11, 4, 6, 7, 3, 8, 5, 5, 9, 2, 7, 11, 1, 12, 9, 1, 10, 3, 11, 14, 1, 5, 13, 3, 13, 2, 11, 4, 13, 1, 8, 7, 13, 4, 11, 9, 7, 16, 2
Offset: 1

Views

Author

Reinhard Zumkeller, Nov 10 2012

Keywords

Comments

a(n) = numerator of A176352(n) / A176352(n+1).

Links

Crossrefs

Cf. A218533 (denominator).

Programs

  • Haskell
    import Data.Ratio ((%), numerator)
a218533 n = a176352 n `div` a218535 n
a218533_list = map numerator $ zipWith (%) a176352_list $ tail a176352_list

Formula

a(n) = A176352(n) / A218535(n).

A218535 Greatest common divisor of consecutive terms in A176352.

Original entry on oeis.org

1, 2, 3, 3, 4, 4, 5, 5, 15, 9, 3, 5, 5, 25, 35, 14, 7, 7, 8, 4, 7, 7, 7, 14, 42, 42, 30, 18, 8, 16, 20, 10, 25, 45, 27, 27, 33, 11, 11, 11, 33, 33, 33, 24, 6, 9, 9, 12, 15, 15, 21, 21, 42, 66, 36, 108, 117, 13, 65, 91, 91, 91, 13, 13, 39, 33, 22, 22, 11, 13
Offset: 1

Views

Author

Reinhard Zumkeller, Nov 10 2012

Keywords

Comments

a(n) = gcd(A176352(n),A176352(n+1)).

Links

Crossrefs

Cf. A176352, A218533, A218534.

Programs

  • Haskell
    import Data.Ratio ((%), numerator, denominator)
a218535 n = a218535_list !! (n-1)
a218535_list = zipWith gcd a176352_list $ tail a176352_list
-- .

A218534 Denominators of the ratios of consecutive terms in A176352.

Original entry on oeis.org

2, 3, 1, 4, 1, 5, 1, 6, 3, 1, 5, 2, 5, 7, 2, 3, 1, 8, 1, 7, 3, 7, 2, 9, 4, 5, 3, 4, 2, 10, 3, 5, 9, 6, 1, 11, 1, 8, 1, 12, 7, 5, 8, 1, 9, 7, 4, 10, 5, 7, 9, 4, 11, 6, 3, 13, 1, 5, 14, 3, 11, 2, 1, 15, 11, 2, 13, 1, 13, 4, 13, 3, 16, 7, 9, 4, 11, 6, 7, 8, 1
Offset: 1

Views

Author

Reinhard Zumkeller, Nov 10 2012

Keywords

Comments

a(n) = denominator of A176352(n) / A176352(n+1).

Links

Crossrefs

Cf. A218533 (numerator).

Programs

  • Haskell
    import Data.Ratio ((%), denominator)
a218534 n = a176352 (n + 1) `div` a218535 n
a218534_list = map denominator $ zipWith (%) a176352_list $ tail a176352_list

Formula

a(n) = A176352(n+1) / A218535(n).

A218454 Smallest number m such that A176352(m) = n.

Original entry on oeis.org

1, 2, 4, 6, 8, 3, 18, 20, 11, 13, 40, 5, 64, 24, 12, 30, 395, 82, 120, 7, 22, 69, 172, 45, 14, 224, 36, 21, 23163, 9, 501, 124, 38, 325, 93, 48, 424, 389, 73, 107, 10424, 17, 588, 125, 10, 591, 39202, 143, 23, 33, 150, 71, 18422, 46, 94, 19, 203, 931, 1085
Offset: 1

Views

Author

Reinhard Zumkeller, Oct 30 2012

Keywords

Comments

A176352(a(n)) = n; if A176352 is a permutation of the natural numbers, then this sequence is its inverse.

Links

Programs

  • Haskell
    import Data.List (elemIndex)
import Data.Maybe (fromJust)
a218454 = (+ 1) . fromJust . (`elemIndex` a176352_list)
Showing 1-4 of 4 results.

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

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