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 1-4 of 4 results.

A297162 Restricted growth sequence transform of A297172, which is Möbius transform of A253564.

Original entry on oeis.org

1, 2, 3, 2, 4, 2, 5, 6, 3, 3, 7, 3, 8, 4, 3, 9, 10, 6, 11, 4, 12, 5, 13, 14, 4, 7, 14, 5, 15, 3, 16, 17, 18, 8, 4, 9, 19, 10, 20, 21, 22, 4, 23, 7, 12, 11, 24, 25, 5, 9, 26, 8, 27, 9, 18, 28, 29, 13, 30, 31, 32, 15, 18, 33, 34, 5, 35, 10, 36, 31, 37, 17, 38, 16, 14, 11, 5, 7, 39, 40, 25, 19, 41, 42, 43, 22, 44, 45, 46, 14, 20, 13, 47, 23
Offset: 1

Views

Author

Antti Karttunen, Dec 27 2017

Keywords

Crossrefs

Programs

  • PARI
    up_to = 8192;
    rgs_transform(invec) = { my(occurrences = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(occurrences,invec[i]), my(pp = mapget(occurrences, invec[i])); outvec[i] = outvec[pp] , mapput(occurrences,invec[i],i); outvec[i] = u; u++ )); outvec; };
    write_to_bfile(start_offset,vec,bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }
    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)};
    A122111(n) = if(1==n,n,prime(bigomega(n))*A122111(A064989(n)));
    A156552(n) = if(1==n, 0, if(!(n%2), 1+(2*A156552(n/2)), 2*A156552(A064989(n))));
    A253564(n) = A156552(A122111(n));
    A297172(n) = sumdiv(n,d,moebius(n/d)*A253564(d));
    write_to_bfile(1,rgs_transform(vector(up_to,n,A297172(n))),"b297162.txt");

A297112 Möbius transform of A156552.

Original entry on oeis.org

0, 1, 2, 2, 4, 2, 8, 4, 4, 4, 16, 4, 32, 8, 4, 8, 64, 4, 128, 8, 8, 16, 256, 8, 8, 32, 8, 16, 512, 4, 1024, 16, 16, 64, 8, 8, 2048, 128, 32, 16, 4096, 8, 8192, 32, 8, 256, 16384, 16, 16, 8, 64, 64, 32768, 8, 16, 32, 128, 512, 65536, 8, 131072, 1024, 16, 32, 32, 16, 262144, 128, 256, 8, 524288, 16, 1048576, 2048, 8
Offset: 1

Views

Author

Antti Karttunen, Dec 26 2017

Keywords

Crossrefs

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))));
    A297112(n) = sumdiv(n,d,moebius(n/d)*A156552(d));
    
  • Scheme
    ;; With memoization-macro definec.
    (definec (A297112 n) (cond ((<= n 2) (- n 1)) ((odd? n) (* 2 (A297112 (A064989 n)))) ((= 2 (modulo n 4)) (A297112 (/ n 2))) (else (* 2 (A297112 (/ n 2)))))) ;; Antti Karttunen, Dec 27 2017

Formula

a(1) = 0, a(2) = 1, after which, a(2n+1) = 2*a(A064989(2n+1)), a(4n) = 2*a(2n), a(4n+2) = a(2n+1).
a(n) = Sum_{d|n} A008683(n/d)*A156552(d).
For n > 1, a(n) = A000079(A297113(n)-1).

A297171 Möbius transform of A243071.

Original entry on oeis.org

0, 1, 3, 1, 7, 2, 15, 2, 2, 6, 31, 5, 63, 14, 3, 4, 127, 2, 255, 13, 11, 30, 511, 10, 4, 62, 4, 29, 1023, 4, 2047, 8, 27, 126, 5, 4, 4095, 254, 59, 26, 8191, 12, 16383, 61, 10, 510, 32767, 20, 8, 4, 123, 125, 65535, 4, 21, 58, 251, 1022, 131071, 7, 262143, 2046, 26, 16, 53, 28, 524287, 253, 507, 6, 1048575, 8
Offset: 1

Views

Author

Antti Karttunen, Dec 26 2017

Keywords

Crossrefs

Cf. A008683, A064989, A243071, A297161 (rgs-transform of this sequence).
Cf. also A297112, A297156, 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)};
    A243071(n) = if(n<=2, n-1, if(!(n%2), 2*A243071(n/2), 1+(2*A243071(A064989(n)))));
    A297171(n) = sumdiv(n,d,moebius(n/d)*A243071(d));

Formula

a(n) = Sum_{d|n} A008683(n/d)*A243071(d).

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

Views

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));
Showing 1-4 of 4 results.