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 1-2 of 2 results.

A102472 Triangle read by rows. Let S(k) be the sequence defined by F(0)=0, F(1)=1, F(n-1) + (n+k)*F(n) = F(n+1). E.g. S(0) = 0, 1, 1, 3, 10, 43, 225, 1393, 9976, 81201, ... Then S(0), S(1), S(2), ... are written vertically, next to each other, with the initial term of each on the next row down.

Original entry on oeis.org

1, 1, 1, 3, 2, 1, 10, 7, 3, 1, 43, 30, 13, 4, 1, 225, 157, 68, 21, 5, 1, 1393, 972, 421, 130, 31, 6, 1, 9976, 6961, 3015, 931, 222, 43, 7, 1, 81201, 56660, 24541, 7578, 1807, 350, 57, 8, 1, 740785, 516901, 223884, 69133, 16485, 3193, 520, 73, 9, 1
Offset: 1

Views

Author

Russell Walsmith, Jan 09 2005

Keywords

Comments

T(n,1) = A001040(n); T(n,k) = A058294(n,n+k-1), k = 1..n. - Reinhard Zumkeller, Sep 14 2014
This triangle results when the first column is removed from A062323. - Georg Fischer, Jul 26 2023

Examples

			Triangle begins:
[1] 1;
[2] 1, 1;
[3] 3, 2, 1;
[4] 10, 7, 3, 1;
[5] 43, 30, 13, 4, 1;
[6] 225, 157, 68, 21, 5, 1;
[7] 1393, 972, 421, 130, 31, 6, 1;
[8] 9976, 6961, 3015, 931, 222, 43, 7, 1;
		

Crossrefs

Mirror image of triangle in A102473.
Cf. A001040, A058294, A062323, A247365 (central terms).

Programs

  • Haskell
    a102472 n k = a102472_tabl !! (n-1) !! (k-1)
    a102472_row n = a102472_tabl !! (n-1)
    a102472_tabl = map reverse a102473_tabl
    -- Reinhard Zumkeller, Sep 14 2014

Extensions

Entry revised by N. J. A. Sloane, Jul 09 2005

A102473 Triangle read by rows. Let S(k) be the sequence defined by F(0)=0, F(1)=1, F(n-1) + (n+k)*F(n) = F(n+1). E.g. S(0) = 0,1,1,3,10,43,225,1393,9976,81201, ... Then S(0), S(1), S(2), ... are written next to each other, vertically, with the initial term of each on the next row down. The order of the terms in the rows are then reversed.

Original entry on oeis.org

1, 1, 1, 1, 2, 3, 1, 3, 7, 10, 1, 4, 13, 30, 43, 1, 5, 21, 68, 157, 225, 1, 6, 31, 130, 421, 972, 1393, 1, 7, 43, 222, 931, 3015, 6961, 9976, 1, 8, 57, 350, 1807, 7578, 24541, 56660, 81201, 1, 9, 73, 520, 3193, 16485, 69133, 223884, 516901, 740785, 1, 10, 91, 738
Offset: 1

Views

Author

Russell Walsmith (russw(AT)lycos.com), Jan 09 2005

Keywords

Comments

For this triangle, the algorithm that generates the Bernoulli numbers gives 3/2, then 1/6, 1/24, ... 1/n!
T(n,n) = A001040(n); T(n,k) = A058294(n,k), k = 1..n. - Reinhard Zumkeller, Sep 14 2014

Examples

			Triangle begins:
0
0 1
0 1 1
0 1 2 3
0 1 3 7 10
0 1 4 13 30 43
...
(the zeros are omitted).
		

Crossrefs

Mirror image of triangle in A102472.
Cf. A001040, A058294, A247365 (central terms).

Programs

  • Haskell
    a102473 n k = a102473_tabl !! (n-1) !! (k-1)
    a102473_row n = a102473_tabl !! (n-1)
    a102473_tabl = [1] : [1, 1] : f [1] [1, 1] 2 where
       f us vs x = ws : f vs ws (x + 1) where
                   ws = 1 : zipWith (+) ([0] ++ us) (map (* x) vs)
    -- Reinhard Zumkeller, Sep 14 2014

Extensions

Entry revised by N. J. A. Sloane, Jul 09 2005
Showing 1-2 of 2 results.