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.

A167750 Row sums of triangle A167749.

Original entry on oeis.org

1, 1, 2, 4, 9, 20, 45, 102, 231, 524, 1189, 2699, 6127, 13910, 31581, 71702, 162796, 369622, 839216, 1905419, 4326211, 9822571, 22301948, 50636130, 114968339, 261033373, 592671205, 1345648489, 3055268857, 6936928864, 15750162908
Offset: 0

Views

Author

Paul Barry, Nov 10 2009

Keywords

Comments

Hankel transform is A167752.

Examples

			G.f. = 1 + x + 2*x^2 + 4*x^3 + 9*x^4 + 20*x^5 + 45*x^6 + 102*x^7 + ...
		

Formula

G.f.: 1/(1-x/(1-x/(1-x^2/(1-x^3/(1-x^4/(1-...)))))) (continued fraction);
G.f.: 1/(1-x*f(x)), f(x) the g.f. of A005169.

A237347 First differences of A078633.

Original entry on oeis.org

3, 3, 2, 3, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2
Offset: 1

Views

Author

Reinhard Zumkeller, Mar 18 2014

Keywords

Comments

a(n) = A078633(n+1) - A078633(n);
2 <= a(n) <= 3;
a(A049068(n)) = 2; a(A002620(n)) = 3;
A237347(n) = abs(A167752(n)) + 2.

Programs

  • Haskell
    a237347 n = a237347_list !! (n-1)
    a237347_list = zipWith (-) (tail a078633_list) a078633_list

A167753 Hankel transform of A167751.

Original entry on oeis.org

1, 1, 0, -1, -1, 0, 0, 1, 0, -1, 0, 0, 0, -1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, -1
Offset: 0

Views

Author

Paul Barry, Nov 10 2009

Keywords

Comments

The nonzero terms appear to be indexed by ceiling((n+1)^2/4) - 0^n (see A004652).

Crossrefs

Cf. A167752.
Showing 1-3 of 3 results.