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.

A297156 Möbius transform of A243354.

Original entry on oeis.org

0, 1, 3, 1, 7, 2, 15, 3, 1, 6, 31, 6, 63, 14, 2, 5, 127, 2, 255, 14, 10, 30, 511, 10, 1, 62, 7, 30, 1023, 4, 2047, 11, 26, 126, 2, 2, 4095, 254, 58, 26, 8191, 12, 16383, 62, 14, 510, 32767, 22, 1, 2, 122, 126, 65535, 6, 18, 58, 250, 1022, 131071, 4, 262143, 2046, 30, 21, 50, 28, 524287, 254, 506, 4, 1048575, 6
Offset: 1

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Author

Antti Karttunen, Dec 28 2017

Keywords

Crossrefs

Cf. A006068, A156552, A243354, A297157 (rgs-transform of this sequence).
Cf. also A297112, A297171, A297172.

Programs

  • PARI
    A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};
    A156552(n) = if(1==n, 0, if(!(n%2), 1+(2*A156552(n/2)), 2*A156552(A064989(n))));
    A006068(n)= { my(s=1, ns); while(1, ns = n >> s; if(0==ns, break()); n = bitxor(n, ns); s <<= 1; ); return (n); } \\ Essentially Joerg Arndt's Jul 19 2012 code.
    A243354(n) = A006068(A156552(n));
    A297156(n) = sumdiv(n,d,moebius(n/d)*A243354(d));