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.

Previous Showing 21-30 of 30 results.

A324180 SumXOR variant of A297168.

Original entry on oeis.org

0, 0, 0, 1, 0, 3, 0, 3, 2, 5, 0, 3, 0, 9, 6, 7, 0, 5, 0, 3, 10, 17, 0, 3, 4, 33, 6, 3, 0, 5, 0, 15, 18, 65, 12, 7, 0, 129, 34, 15, 0, 9, 0, 3, 6, 257, 0, 3, 8, 9, 66, 3, 0, 9, 20, 23, 130, 513, 0, 15, 0, 1025, 6, 31, 36, 17, 0, 3, 258, 9, 0, 3, 0, 2049, 10, 3, 24, 33, 0, 23, 14, 4097, 0, 23, 68, 8193, 514, 39, 0, 9, 40, 3
Offset: 1

Views

Author

Antti Karttunen, Feb 19 2019

Keywords

Crossrefs

Cf. A061395, A156552, A297106, A297112, A297167, A297168, A324181 (rgs-transform), A324120 (number of 1-bits).

Programs

  • PARI
    A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1])));
    A297167(n) = if(1==n, 0, (A061395(n) + (bigomega(n)-omega(n)) - 1));
    A297112(n) = if(1==n, 0, 2^A297167(n));
    A324180(n) = { my(v=0); fordiv(n, d, if(dA297112(d)))); (v); };

Formula

a(n) = Cumulative XOR of A297112(d), where d ranges over the proper divisors d of n.

A324196 Lexicographically earliest sequence such that a(i) = a(j) => A324195(i) = A324195(j) for all i, j >= 1.

Original entry on oeis.org

1, 2, 3, 4, 5, 4, 6, 7, 8, 9, 10, 7, 11, 12, 8, 13, 14, 7, 15, 13, 16, 17, 18, 13, 19, 20, 21, 22, 23, 7, 24, 25, 26, 27, 19, 13, 28, 29, 30, 25, 31, 32, 33, 34, 21, 35, 36, 25, 37, 38, 39, 40, 41, 13, 42, 43, 44, 45, 46, 13, 47, 48, 49, 43, 50, 51, 52, 53, 54, 38, 55, 25, 56, 57, 21, 58, 37, 59, 60, 43, 49, 61, 62, 25, 63, 64, 65, 66, 67, 13, 68, 69, 70, 71, 72, 43
Offset: 1

Views

Author

Antti Karttunen, Feb 20 2019

Keywords

Comments

Restricted growth sequence transform of A324195.
For all i, j: a(i) = a(j) => A324197(i) = A324197(j) => A324190(i) = A324190(j).

Crossrefs

Programs

  • PARI
    up_to = 65537;
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1])));
    A297167(n) = if(1==n, 0, (A061395(n) + (bigomega(n)-omega(n)) - 1));
    A297112(n) = if(1==n, 0, 2^A297167(n));
    A324195(n) = { my(v=0); fordiv(n, d, v = bitor(v,A297112(d))); (v); };
    v324196 = rgs_transform(vector(up_to, n, A324195(n)));
    A324196(n) = v324196[n];

A324197 Lexicographically earliest sequence such that a(i) = a(j) => f(i) = f(j), where f(n) = A324195(n) for all other numbers except f(2) = -1 and f(n) = -2 when n is an odd prime.

Original entry on oeis.org

1, 2, 3, 4, 3, 4, 3, 5, 6, 7, 3, 5, 3, 8, 6, 9, 3, 5, 3, 9, 10, 11, 3, 9, 12, 13, 14, 15, 3, 5, 3, 16, 17, 18, 12, 9, 3, 19, 20, 16, 3, 21, 3, 22, 14, 23, 3, 16, 24, 25, 26, 27, 3, 9, 28, 29, 30, 31, 3, 9, 3, 32, 33, 29, 34, 35, 3, 36, 37, 25, 3, 16, 3, 38, 14, 39, 24, 40, 3, 29, 33, 41, 3, 16, 42, 43, 44, 45, 3, 9, 46, 47, 48, 49, 50, 29, 3, 51, 52, 16, 3, 53, 3, 54, 14
Offset: 1

Views

Author

Antti Karttunen, Feb 20 2019

Keywords

Comments

For all i, j: a(i) = a(j) => A324190(i) = A324190(j).

Crossrefs

Programs

  • PARI
    up_to = 65537;
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1])));
    A297167(n) = if(1==n, 0, (A061395(n) + (bigomega(n)-omega(n)) - 1));
    A297112(n) = if(1==n, 0, 2^A297167(n));
    A324195(n) = { my(v=0); fordiv(n, d, v = bitor(v,A297112(d))); (v); };
    Aux324197(n) = if(isprime(n),-(n%2)-1,A324195(n));
    v324197 = rgs_transform(vector(up_to, n, Aux324197(n)));
    A324197(n) = v324197[n];

A329372 Dirichlet convolution of the identity function with A156552.

Original entry on oeis.org

0, 1, 2, 5, 4, 12, 8, 17, 12, 22, 16, 44, 32, 40, 32, 49, 64, 61, 128, 78, 56, 76, 256, 132, 32, 142, 50, 136, 512, 152, 1024, 129, 104, 274, 88, 209, 2048, 532, 188, 230, 4096, 256, 8192, 252, 148, 1048, 16384, 356, 80, 159, 356, 454, 32768, 240, 160, 392, 680, 2078, 65536, 504, 131072, 4128, 248, 321, 280, 464, 262144, 858, 1328, 400
Offset: 1

Views

Author

Antti Karttunen, Nov 12 2019

Keywords

Comments

Equally, Dirichlet convolution of sigma (A000203) with A297112 (Möbius transform of A156552).

Crossrefs

Programs

  • PARI
    A156552(n) = {my(f = factor(n), p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res}; \\ From A156552
    A329372(n) = sumdiv(n,d,(n/d)*A156552(d));
    
  • PARI
    A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1])));
    A297167(n) = if(1==n, 0, (A061395(n) + (bigomega(n)-omega(n)) - 1));
    A297112(n) = if(1==n,0,2^A297167(n));
    A329372(n) = sumdiv(n,d,sigma(n/d)*A297112(d));

Formula

a(n) = Sum_{d|n} d * A156552(n/d).
a(n) = Sum_{d|n} A000203(n/d) * A297112(d).
A000265(a(n)) = A329374(n).

A364568 a(n) = A290077(n) - A364567(n).

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 2, 0, -2, 0, 4, 0, 12, 2, 10, 0, -6, -2, 4, 0, 16, 4, 16, 0, 26, 12, 32, 4, 84, 10, 38, 0, -20, -6, 4, -4, 24, 4, 20, 0, 44, 16, 40, 8, 104, 16, 56, 0, 78, 26, 68, 24, 152, 32, 104, 8, 262, 84, 184, 20, 468, 38, 130, 0, -48, -20, -8, -12, 16, 4, 28, -8, 40, 24, 64, 8, 168, 20, 76, 0, 88, 44, 104, 32
Offset: 0

Views

Author

Antti Karttunen, Aug 05 2023

Keywords

Crossrefs

Programs

  • PARI
    A290077(n) = { my(p=2,z=1); while(n, if(!(n%2), p=nextprime(1+p), z *= (p-(1==(n%4)))); n>>=1); (z); };
    A364567(n) = if(!n,n, my(i=1); while(n>1, if((n%4)!=1, i<<=1); n >>= 1); (i));
    A364568(n) = (A290077(n) - A364567(n));

Formula

For n > 0, a(n) = -A364558(A005940(1+n)) = A000010(A005940(1+n)) - 2^A033265(n).

A297169 Restricted growth sequence transform of a(1) = -1, a(n) = A297168(n) for n > 1.

Original entry on oeis.org

1, 2, 2, 3, 2, 4, 2, 4, 5, 6, 2, 7, 2, 8, 9, 7, 2, 8, 2, 10, 11, 12, 2, 13, 14, 15, 9, 16, 2, 12, 2, 13, 17, 18, 19, 16, 2, 20, 21, 22, 2, 23, 2, 24, 25, 26, 2, 27, 28, 12, 29, 30, 2, 31, 32, 33, 34, 35, 2, 24, 2, 36, 37, 27, 38, 39, 2, 40, 41, 15, 2, 33, 2, 42, 17, 43, 44, 45, 2, 46, 25, 47, 2, 48, 49, 50, 51, 52, 2, 53, 54, 55, 56, 57, 58, 59, 2, 15, 60, 24
Offset: 1

Views

Author

Antti Karttunen, Feb 27 2018

Keywords

Comments

For all i, j: A300827(i) = A300827(j) => a(i) = a(j). - Antti Karttunen, Mar 13 2018

Crossrefs

Programs

  • PARI
    allocatemem(2^30);
    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])); }
    A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1])));
    A297167(n) = if(1==n, 0, (A061395(n) + (bigomega(n)-omega(n)) - 1));
    A297112(n) = if(1==n,0,2^A297167(n));
    A297168v1(n) = if(1==n,-1,sumdiv(n,d,(dA297112(d)));
    write_to_bfile(1,rgs_transform(vector(up_to,n,A297168v1(n))),"b297169.txt");
    \\ (More efficient PARI program) - Antti Karttunen, Mar 13 2018

A323914 Lexicographically earliest sequence such that a(i) = a(j) => A322994(i) = A322994(j), for all i, j >= 1.

Original entry on oeis.org

1, 2, 2, 3, 2, 4, 2, 5, 3, 6, 2, 5, 2, 7, 4, 8, 2, 9, 2, 8, 6, 10, 2, 8, 3, 11, 5, 12, 2, 13, 2, 12, 7, 14, 4, 8, 2, 15, 10, 12, 2, 16, 2, 17, 5, 18, 2, 12, 3, 19, 11, 20, 2, 21, 6, 17, 14, 22, 2, 8, 2, 23, 8, 17, 7, 24, 2, 25, 15, 26, 2, 12, 2, 27, 9, 28, 4, 29, 2, 17, 8, 30, 2, 12, 10, 31, 18, 20, 2, 21, 6, 32, 22, 33, 11, 17, 2, 34, 12, 12, 2, 35, 2, 25, 13
Offset: 1

Views

Author

Antti Karttunen, Feb 12 2019

Keywords

Comments

Restricted growth sequence transform of A322994.

Crossrefs

Programs

  • PARI
    up_to = 65537;
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A000265(n) = (n/2^valuation(n, 2));
    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))));
    A322993(n) = if(1==n,0,A000265(A156552(n)));
    A322994(n) = sumdiv(n,d,moebius(n/d)*A322993(d));
    v323914 = rgs_transform(vector(up_to,n,A322994(n)));
    A323914(n) = v323914[n];

A329374 a(1) = 0; for n > 1, a(n) = A000265(A329372(n)), where A329372 is Dirichlet convolution of the identity function with A156552.

Original entry on oeis.org

0, 1, 1, 5, 1, 3, 1, 17, 3, 11, 1, 11, 1, 5, 1, 49, 1, 61, 1, 39, 7, 19, 1, 33, 1, 71, 25, 17, 1, 19, 1, 129, 13, 137, 11, 209, 1, 133, 47, 115, 1, 1, 1, 63, 37, 131, 1, 89, 5, 159, 89, 227, 1, 15, 5, 49, 85, 1039, 1, 63, 1, 129, 31, 321, 35, 29, 1, 429, 83, 25, 1, 605, 1, 4115, 111, 409, 15, 101, 1, 307, 45, 8213, 1, 13, 65, 8203, 655, 179, 1, 335, 25
Offset: 1

Views

Author

Antti Karttunen, Nov 12 2019

Keywords

Crossrefs

Programs

Formula

a(1) = 0; and for n > 1, a(n) = A000265(A329372(n)).

A329034 Möbius transform of A122111.

Original entry on oeis.org

1, 1, 3, 1, 7, 1, 15, 2, 5, 3, 31, 3, 63, 7, 7, 2, 127, 4, 255, 7, 17, 15, 511, 2, 19, 31, 16, 15, 1023, 7, 2047, 4, 37, 63, 31, 2, 4095, 127, 77, 6, 8191, 15, 16383, 31, 27, 255, 32767, 6, 65, 14, 157, 63, 65535, 4, 69, 14, 317, 511, 131071, 1, 262143, 1023, 59, 2, 145, 31, 524287, 127, 637, 25, 1048575, 8, 2097151, 2047, 38, 255, 115, 63
Offset: 1

Views

Author

Antti Karttunen, Nov 08 2019

Keywords

Comments

a(144) = -2 is the first negative term.

Crossrefs

Cf. also A297112.

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)};
    A122111(n) = if(1==n,n,prime(bigomega(n))*A122111(A064989(n)));
    A329034(n) = sumdiv(n,d,moebius(n/d)*A122111(d));

Formula

a(n) = Sum_{d|n} A008683(n/d)*A122111(d).

A324285 a(n) = A002487(A297168(n)).

Original entry on oeis.org

0, 0, 0, 1, 0, 2, 0, 2, 1, 3, 0, 3, 0, 4, 2, 3, 0, 4, 0, 5, 3, 5, 0, 4, 1, 6, 2, 7, 0, 5, 0, 4, 4, 7, 2, 7, 0, 8, 5, 7, 0, 7, 0, 9, 3, 9, 0, 5, 1, 5, 6, 11, 0, 8, 3, 10, 7, 10, 0, 9, 0, 11, 5, 5, 4, 13, 0, 13, 8, 6, 0, 10, 0, 12, 4, 15, 2, 19, 0, 9, 3, 13, 0, 11, 5, 14, 9, 13, 0, 11, 3, 17, 10, 15, 6, 6, 0, 6, 7, 9, 0, 25, 0, 16, 5
Offset: 1

Views

Author

Antti Karttunen, Feb 22 2019

Keywords

Crossrefs

Programs

Formula

a(n) = A002487(A297168(n)).
Previous Showing 21-30 of 30 results.