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.

A124139 a(n) = A000265(3*(a(n-1) + a(n-2))/2 + 1) starting at a(1)=1, a(2)=11.

Original entry on oeis.org

1, 11, 19, 23, 1, 37, 29, 25, 41, 25, 25, 19, 67, 65, 199, 397, 895, 1939, 1063, 563, 305, 1303, 2413, 5575, 11983, 13169, 37729, 19087, 85225, 156469, 181271, 506611, 64489, 856651, 1381711, 419693, 2702107, 4682701, 11077213, 369373, 2146235, 3773413
Offset: 1

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Author

Yasutoshi Kohmoto, Dec 01 2006

Keywords

Comments

A variant of A105801: The highest power of two is recursively removed from 3x/2+1, where x is the sum of the preceding two elements of the sequence.

Crossrefs

Cf. A124138.

Programs

  • Maple
    A000265 := proc(n) local a,nshft ; a := 1 ; nshft := n ; while nshft mod 2 = 0 do nshft := nshft/2 ; od: nshft ; end:
    A124139 := proc(n) option remember ; if n = 1 then 1; elif n = 2 then 11; else A000265(3*(procname(n-1)+procname(n-2))/2 +1) ; fi; end: seq(A124139(n),n=1..60) ; # R. J. Mathar, Jul 02 2009

Extensions

Edited and extended by R. J. Mathar, Jul 02 2009