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.

A108396 Triangle read by rows: T(n,k) = n*(1+n^k)/2, 0<=k<=n.

Original entry on oeis.org

0, 1, 1, 2, 3, 5, 3, 6, 15, 42, 4, 10, 34, 130, 514, 5, 15, 65, 315, 1565, 7815, 6, 21, 111, 651, 3891, 23331, 139971, 7, 28, 175, 1204, 8407, 58828, 411775, 2882404, 8, 36, 260, 2052, 16388, 131076, 1048580, 8388612, 67108868, 9, 45, 369, 3285, 29529, 265725
Offset: 0

Views

Author

Reinhard Zumkeller, Jun 02 2005

Keywords

Comments

Row sums give A108397;
T(n,0) = A001477(n);
T(n,1) = A000217(n) for n>0;
T(n,2) = A006003(n) for n>1;
T(n,3) = A027441(n) for n>2;
T(n,4) = A021003(n) for n>3;
T(n,n) = A108398(n).

Examples

			.  0:  0
.  1:  1  1
.  2:  2  3   5
.  3:  3  6  15   42
.  4:  4 10  34  130   514
.  5:  5 15  65  315  1565   7815
.  6:  6 21 111  651  3891  23331  139971
.  7:  7 28 175 1204  8407  58828  411775  2882404
.  8:  8 36 260 2052 16388 131076 1048580  8388612  67108868
.  9:  9 45 369 3285 29529 265725 2391489 21523365 193710249 1743392205 .
		

Crossrefs

Cf. A079901, A000312, A033918, A001477, A000217, A006003, A027441, A021003, A108398, A108397 (row sums), A256512 (central terms).

Programs

  • Haskell
    a108396 n k = a108396_tabl !! n !! k
    a108396_row n = a108396_tabl !! n
    a108396_tabl = zipWith (\v ws -> map (flip div 2 . (* v) . (+ 1)) ws)
                           [0..] a079901_tabl
    -- Reinhard Zumkeller, Mar 31 2015
  • Mathematica
    Join[{0},Flatten[Table[n (1+n^k)/2,{n,10},{k,0,n}]]] (* Harvey P. Dale, Mar 19 2015 *)

Extensions

Offset changed by Reinhard Zumkeller, Mar 31 2015

A256512 n*(1+(2*n)^n).

Original entry on oeis.org

0, 3, 34, 651, 16388, 500005, 17915910, 737894535, 34359738376, 1785233613321, 102400000000010, 6427501315524619, 438244169232678924, 32254987351648575501, 2548827677619195478030, 215233605000000000000015, 19342813113834066795298832
Offset: 0

Views

Author

Reinhard Zumkeller, Mar 31 2015

Keywords

Comments

a(n) = A108396(2*n,n): central terms of the triangle A108396.

Crossrefs

Programs

  • Haskell
    a256512 n = n * (1 + (2 * n) ^ n)
  • Mathematica
    Join[{0},Table[n(1+(2n)^n),{n,20}]] (* Harvey P. Dale, Aug 05 2021 *)

A322406 a(n) = n + n*n^n.

Original entry on oeis.org

2, 10, 84, 1028, 15630, 279942, 5764808, 134217736, 3486784410, 100000000010, 3138428376732, 106993205379084, 3937376385699302, 155568095557812238, 6568408355712890640, 295147905179352825872, 14063084452067724991026, 708235345355337676357650, 37589973457545958193355620
Offset: 1

Views

Author

Ivan Stoykov, Dec 07 2018

Keywords

Comments

All terms are produced by successively applying the three basic operations: exponentiation, multiplication and addition.

Examples

			a(3) = 3 + 3*3^3 = 3 + 3*27 = 8 + 81 = 84.
		

Crossrefs

Equals 2 * A108398.

Programs

Formula

E.g.f.: exp(x) * x - LambertW(-x)/(1 + LambertW(-x))^3. - Vaclav Kotesovec, Dec 20 2018

Extensions

a(12)-a(19) from Stefano Spezia, Dec 07 2018
Showing 1-3 of 3 results.