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.

A152978 a(n) = A139251(n+2)/4 = A152968(n+1)/2.

Original entry on oeis.org

1, 1, 1, 2, 3, 2, 1, 2, 3, 3, 4, 7, 8, 4, 1, 2, 3, 3, 4, 7, 8, 5, 4, 7, 9, 10, 15, 22, 20, 8, 1, 2, 3, 3, 4, 7, 8, 5, 4, 7, 9, 10, 15, 22, 20, 9, 4, 7, 9, 10, 15, 22, 21, 14, 15, 23, 28, 35, 52, 64, 48, 16, 1, 2, 3, 3, 4, 7, 8, 5, 4, 7, 9, 10, 15, 22, 20, 9, 4, 7, 9, 10, 15, 22, 21, 14, 15, 23
Offset: 1

Views

Author

Omar E. Pol, Dec 16 2008, Dec 20 2008

Keywords

Comments

Also, first differences of toothpick numbers A153000.

Examples

			If written as a triangle, begins:
.1,1;
.1,2,3,2;
.1,2,3,3,4,7,8,4;
.1,2,3,3,4,7,8,5,4,7,9,10,15,22,20,8;
....
Rows converge to A152980.
It appears that row sums give A004171. [From _Omar E. Pol_, May 25 2010]
		

Crossrefs

Cf. toothpick sequence A139250.
Cf. A004171. [From Omar E. Pol, May 25 2010]

Formula

G.f.: (1+x)*(Prod(1+x^(2^k-1)+2*x^(2^k),k=1..oo)-1)/(1+2*x). - N. J. A. Sloane, May 20 2009

Extensions

More terms from Omar E. Pol, Jul 26 2009

A152979 Records in A152978.

Original entry on oeis.org

1, 2, 3, 4, 7, 8, 9, 10, 15, 22, 23, 28, 35, 52, 64, 65, 74, 91, 122, 168, 176, 177, 186, 239, 304, 412, 512, 513, 524, 527, 599, 782, 1020, 1336, 1488, 1489, 1500, 1575, 1980, 2584, 3376, 4160, 4161, 4172, 4174, 4247, 4275, 4653, 5010, 6544, 8544
Offset: 1

Views

Author

Omar E. Pol, Dec 23 2008

Keywords

Comments

This sequence also gives the records in A152980. - Nathaniel Johnston, Apr 10 2011

Crossrefs

Extensions

a(16)-a(51) from Nathaniel Johnston, Apr 10 2011

A153838 Records in A153004.

Original entry on oeis.org

1, 3, 6, 9, 12, 21, 24, 27, 30, 45, 66, 69, 84, 105, 156, 192, 195, 222, 273, 366, 504, 528, 531, 558, 717, 912, 1236, 1536, 1539, 1572, 1581, 1797, 2346, 3060, 4008, 4464, 4467, 4500, 4725, 5940, 7752, 10128, 12480, 12483, 12516, 12522, 12741, 12825, 13959
Offset: 1

Views

Author

Omar E. Pol, Jan 02 2009

Keywords

Crossrefs

Programs

  • Maple
    read("transforms3") : a139250 := BFILETOLIST("b139250.txt") : A139250 := proc(n) global a139250; op(n+1,a139250) ; end: A153003 := proc(n) if n =0 then 0; else 1+3/4*(A139250(n+1)-3) ; fi; end: A153004 := proc(n) A153003(n)-A153003(n-1) ; end: rec := -1 ; for n from 1 to 3000 do t := A153004(n) ; if t > rec then printf("%d,",t) ; rec := t; fi; od: # R. J. Mathar, Jul 13 2009

Extensions

More terms from R. J. Mathar, Jul 13 2009
Showing 1-3 of 3 results.