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.

A037839 a(n) = Sum{|d(i)-d(i-1)|: i=1,...,m}, where Sum{d(i)*7^i: i=0,1,...,m} is the base 7 representation of n.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 0, 1, 2, 3, 4, 5, 2, 1, 0, 1, 2, 3, 4, 3, 2, 1, 0, 1, 2, 3, 4, 3, 2, 1, 0, 1, 2, 5, 4, 3, 2, 1, 0, 1, 6, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 1, 0, 1, 2, 3, 4, 5, 3, 2, 1, 2, 3, 4, 5, 5, 4, 3, 2, 3, 4, 5, 7, 6, 5, 4, 3, 4, 5, 9, 8, 7, 6, 5, 4, 5
Offset: 1

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Keywords

Comments

This is the base-7 total variation sequence; see A297330. - Clark Kimberling, Jan 18 2017

Crossrefs

Cf. A297330.

Programs

  • Mathematica
    b = 7; z = 120; t = Table[Total@Flatten@Map[Abs@Differences@# &, Partition[IntegerDigits[n, b], 2, 1]], {n, z}] (* cf. Michael De Vlieger, A037834 *)

Extensions

Updated by Clark Kimberling, Jan 20 2018