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.

A129096 A bisection of A129095: a(n) = A129095(2n-1) for n>=1.

Original entry on oeis.org

1, 3, 5, 11, 13, 23, 29, 51, 53, 79, 89, 135, 141, 199, 221, 323, 325, 431, 457, 615, 625, 803, 849, 1119, 1125, 1407, 1465, 1863, 1885, 2327, 2429, 3075, 3077, 3727, 3833, 4695, 4721, 5635, 5793, 7023, 7033, 8283, 8461, 10067, 10113, 11811, 12081, 14319
Offset: 1

Views

Author

Paul D. Hanna, Apr 11 2007

Keywords

Comments

b(n)=A129095(n) obeys the recurrence: b(n) = b(n/2) (n even), b(n) = 2*b(n-1) + b(n-2) (n odd >1), with b(1) = 1.

Crossrefs

Programs

  • Mathematica
    With[{s = Nest[Append[#1, If[EvenQ[#2], #1[[#2/2]], 2 #1[[-1]] + #1[[-2]] ] ] & @@ {#, Length@ # + 1} &, {1}, 192]}, Table[s[[i]], {i, 1, Floor[Length[s]/2], 2}]] (* Michael De Vlieger, Mar 10 2020 *)

A129097 a(n) = A129095(2^n - 1) for n>=1.

Original entry on oeis.org

1, 3, 11, 51, 323, 3075, 47427, 1230787, 54772163, 4247022531, 582413946819, 143061847179203, 63604391931367363, 51621812365091401667, 77028054123935294320579, 212592144046864728487817155
Offset: 1

Views

Author

Paul D. Hanna, Apr 11 2007

Keywords

Comments

b(n)=A129095(n) obeys the recurrence: b(n) = b(n/2) (n even), b(n) = 2*b(n-1) + b(n-2) (n odd >1), with b(1) = 1.

Crossrefs

Programs

  • Mathematica
    Block[{e = 16, s}, s = Nest[Append[#1, If[EvenQ[#2], #1[[#2/2]], 2 #1[[-1]] + #1[[-2]] ] ] & @@ {#, Length@ # + 1} &, {1}, 2^e]; Array[s[[2^# - 1]] &, e]] (* Michael De Vlieger, Mar 10 2020 *)
  • PARI
    
    				

A129098 a(n) = A129095(2^n + 2^(n-1) - 1) for n>=1.

Original entry on oeis.org

1, 5, 23, 135, 1119, 14319, 300015, 10636463, 652217135, 70382845743, 13551477257519, 4706105734658351, 2973879284783561007, 3444999327807280048431, 7362415635261959807011119, 29188908702092573515760044335
Offset: 1

Views

Author

Paul D. Hanna, Apr 11 2007

Keywords

Comments

b(n)=A129095(n) obeys the recurrence: b(n) = b(n/2) (n even), b(n) = 2*b(n-1) + b(n-2) (n odd >1), with b(1) = 1.

Crossrefs

Programs

  • Mathematica
    Block[{e = 18, s}, s = Nest[Append[#1, If[EvenQ[#2], #1[[#2/2]], 2 #1[[-1]] + #1[[-2]] ] ] & @@ {#, Length@ # + 1} &, {1}, 2^e]; Array[s[[2^# + 2^(# - 1) - 1]] &, e - 1]] (* Michael De Vlieger, Mar 10 2020 *)
  • PARI
    
    				

Extensions

a(16) from Michael De Vlieger, Mar 10 2020.

A129099 a(n) = Sum_{k=2^(n-1)..2^n-1} A129095(k) for n>=1.

Original entry on oeis.org

1, 4, 20, 136, 1376, 22176, 591680, 26770688, 2096125184, 289083462144, 71239716616192, 31730665042094080, 25779103986580017152, 38488216155785101459456, 106257557996370396596748288, 545336631331873524033714683904
Offset: 1

Views

Author

Paul D. Hanna, Apr 11 2007

Keywords

Comments

b(n)=A129095(n) obeys the recurrence: b(n) = b(n/2) (n even), b(n) = 2*b(n-1) + b(n-2) (n odd >1), with b(1) = 1.

Crossrefs

Programs

  • Mathematica
    Block[{e = 16, s}, s = Nest[Append[#1, If[EvenQ[#2], #1[[#2/2]], 2 #1[[-1]] + #1[[-2]] ] ] & @@ {#, Length@ # + 1} &, {1}, 2^e]; Array[Total@ s[[2^# ;; 2^(# + 1) - 1]] &, e, 0] ] (* Michael De Vlieger, Mar 10 2020 *)
  • PARI
    
    				

Formula

a(n) = ( A129097(n+1) - A129097(n) )/2.

Extensions

a(16) from Michael De Vlieger, Mar 10 2020
Showing 1-4 of 4 results.