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.

A164869 n*A027642(n).

Original entry on oeis.org

0, 2, 12, 3, 120, 5, 252, 7, 240, 9, 660, 11, 32760, 13, 84, 15, 8160, 17, 14364, 19, 6600, 21, 3036, 23, 65520, 25, 156, 27, 24360, 29, 429660, 31, 16320, 33, 204, 35, 69090840, 37, 228, 39, 541200, 41, 75852, 43, 30360, 45, 12972, 47, 2227680, 49, 3300, 51, 82680
Offset: 0

Views

Author

Paul Curtz, Aug 29 2009

Keywords

Crossrefs

Cf. A164877 (bisection).

Formula

a(n) = A164558(n) - A164555(n).
a(n) = A027642(n) * A001477(n).

Extensions

Extended by R. J. Mathar, Sep 03 2009

A228838 a(n) = n * A002445(n).

Original entry on oeis.org

0, 6, 60, 126, 120, 330, 16380, 42, 4080, 7182, 3300, 1518, 32760, 78, 12180, 214830, 8160, 102, 34545420, 114, 270600, 37926, 15180, 6486, 1113840, 1650, 41340, 21546, 24360, 10266, 1703601900, 186, 16320, 2135826, 1020, 164010, 5043631320, 222, 1140
Offset: 0

Views

Author

Paul Curtz, Sep 05 2013

Keywords

Comments

a(n+1) is a multiple of A040031(n+1), sequence of period 2: 6, 12.
a(n) is divisible by A040879(n)=30 followed by the sequence of period 2: 6, 60. See A040214 and A165734.
Note that A164877(n) + A000367(n) = A164558(2n).

Examples

			a(0)=0*1, a(1)=1*6, a(2)=2*30=60,, a(3)=3*42=126.

Links

Programs

  • PARI
    a(n)=n*denominator(bernfrac(2*n))

Formula

a(n) = A176328(2n) - A000367(n).
a(n) = A164877(n)/2.
a(n+1) = A111008(n) * A036283(n+1).
2*a(n) = A164558(2n) - A000367(n).
a(n) = A164558(2n) - A176328(2n).

Extensions

Typo in data fixed by Colin Barker, Jul 03 2015
Showing 1-2 of 2 results.

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