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.

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A098354 Multiplication table of the powers of 2 read by antidiagonals.

Original entry on oeis.org

4, 8, 8, 16, 16, 16, 32, 32, 32, 32, 64, 64, 64, 64, 64, 128, 128, 128, 128, 128, 128, 256, 256, 256, 256, 256, 256, 256, 512, 512, 512, 512, 512, 512, 512, 512, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 2048, 2048, 2048, 2048, 2048, 2048, 2048, 2048
Offset: 1

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Author

Douglas Stones (dssto1(AT)student.monash.edu.au), Sep 04 2004

Keywords

Examples

			4; 8,8; 16,16,16; 32,32,32,32; ...
		

Crossrefs

Programs

A259653 a(0)=0, a(1)=1, a(n) = min{3 a(k) + (3^(n-k)-1)/2, k=0..(n-1)} for n>=2.

Original entry on oeis.org

0, 1, 4, 7, 16, 25, 34, 61, 88, 115, 142, 223, 304, 385, 466, 547, 790, 1033, 1276, 1519, 1762, 2005, 2734, 3463, 4192, 4921, 5650, 6379, 7108, 9295, 11482, 13669, 15856, 18043, 20230, 22417, 24604, 31165, 37726, 44287, 50848, 57409, 63970, 70531, 77092
Offset: 0

Views

Author

Gheorghe Coserea, Jul 02 2015

Keywords

Comments

A generalization of Frame-Stewart recurrence is a(0)=0, a(1)=1, a(n)=min{q*a(k) + (q^(n-k)-1)/(q-1), k=0..(n-1)} where n>=2 and q>1. The sequence of first differences is q^A003056(n). For q=2 we have the sequence A007664. The current sequence is generated for q=3.

Crossrefs

Essentially partial sums of A098355.

Programs

  • Mathematica
    a[n_] := a[n] = Min[ Table[ 3*a[k] + (3^(n-k) - 1)/2, {k, 0, n-1}]]; a[0] = 0; Table[a[n], {n, 0, 60}]

Formula

a(n) = min {3*a(k) + (3^(n-k)-1)/2 ; k < n}.
a(n) = sum(3^A003056(i), i=0..n-1).
Showing 1-2 of 2 results.