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.

A164675 a(n) = 8*a(n-2) for n > 2; a(1) = 1, a(2) = 12.

Original entry on oeis.org

1, 12, 8, 96, 64, 768, 512, 6144, 4096, 49152, 32768, 393216, 262144, 3145728, 2097152, 25165824, 16777216, 201326592, 134217728, 1610612736, 1073741824, 12884901888, 8589934592, 103079215104, 68719476736, 824633720832
Offset: 1

Views

Author

Klaus Brockhaus, Aug 20 2009

Keywords

Comments

Interleaving of A001018 and 12*A001018.
Binomial transform is A164539.

Crossrefs

Cf. A001018 (powers of 8), A164539.

Programs

  • Magma
    [ n le 2 select 11*n-10 else 8*Self(n-2): n in [1..26] ];
  • Mathematica
    Riffle[#, 12*#] & [8^Range[0, 14]] (* or *)
    LinearRecurrence[{0, 8}, {1, 12}, 30] (* Paolo Xausa, Apr 22 2024 *)

Formula

a(n) = (5+(-1)^n)*2^(1/4*(6*n-11+3*(-1)^n)).
G.f.: x*(1+12*x)/(1-8*x^2).

A164540 a(n) = 4*a(n-1) + 4*a(n-2) for n > 1; a(0) = 1, a(1) = 14.

Original entry on oeis.org

1, 14, 60, 296, 1424, 6880, 33216, 160384, 774400, 3739136, 18054144, 87173120, 420909056, 2032328704, 9812951040, 47381118976, 228776280064, 1104629596160, 5333623504896, 25753012404224, 124346543636480, 600398224162816
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 15 2009

Keywords

Comments

Binomial transform of A164539. Second binomial transform of A164675. Inverse binomial transform of A164541.

Crossrefs

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((1+3*r)*(2+2*r)^n+(1-3*r)*(2-2*r)^n)/2: n in [0..21] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 20 2009
  • Mathematica
    LinearRecurrence[{4,4},{1,14},30] (* Harvey P. Dale, Jul 18 2024 *)

Formula

a(n) = 4*a(n-1) + 4*a(n-2) for n > 1; a(0) = 1, a(1) = 14.
G.f.: (1+10*x)/(1-4*x-4*x^2).
a(n) = ((1+3*sqrt(2))*(2+2*sqrt(2))^n + (1-3*sqrt(2))*(2-2*sqrt(2))^n)/2.

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Aug 20 2009
Showing 1-2 of 2 results.