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.

A159912 Partial sums of A159913(k) = 2^bitcount(2k+1)-1 = A038573(2k+1), bitcount=A000120.

Original entry on oeis.org

0, 1, 4, 7, 14, 17, 24, 31, 46, 49, 56, 63, 78, 85, 100, 115, 146, 149, 156, 163, 178, 185, 200, 215, 246, 253, 268, 283, 314, 329, 360, 391, 454, 457, 464, 471, 486, 493, 508, 523, 554, 561, 576, 591, 622, 637, 668, 699, 762, 769, 784, 799, 830, 845, 876, 907
Offset: 0

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Author

M. F. Hasler, May 03 2009

Keywords

Comments

More precisely, a(n)=sum(iA159913(i)), since we want the sequence to start with a(0)=0 and not with A159913(0)=1.
a(n) is also the total number of ON cells after n generations in the outward corner version of the Ulam-Warburton cellular automaton of A147562, and a(n) is also the total number of Y-toothpicks after n generations in the outward corner version of the Y-toothpick structure of A160120. - David Applegate and Omar E. Pol, Jan 24 2016

Crossrefs

Programs

  • Mathematica
    Accumulate@ Table[2^(DigitCount[n, 2][[1]] + 1) - 1, {n, 0, 54}] (* Michael De Vlieger, Jan 25 2016 *)
  • PARI
    A159912(n)=sum(i=0,n-1,1<
    				

Formula

a(n) = sum( i=0...n-1, A159913(i)) = sum(i=0..n-1, 2^A000120(i))*2-n
a(n) = n + (A160720(n) - 1)/2 = n + 2*(A266532(n) - 1)/3 = n + 2*A267700(n-1), n >= 1. - Omar E. Pol, Jan 25 2016