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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A252759 Manhattan distance of n in array A246278 from the top left corner: a(1) = 0; for n>1: a(n) = A055396(n) + A246277(n) - 1.

Original entry on oeis.org

0, 1, 2, 2, 3, 3, 4, 4, 3, 5, 5, 6, 6, 7, 4, 8, 7, 9, 8, 10, 6, 11, 9, 12, 4, 13, 5, 14, 10, 15, 11, 16, 8, 17, 5, 18, 12, 19, 12, 20, 13, 21, 14, 22, 7, 23, 15, 24, 5, 25, 14, 26, 16, 27, 7, 28, 18, 29, 17, 30, 18, 31, 11, 32, 9, 33, 19, 34, 20, 35, 20, 36, 21, 37, 10, 38, 6, 39, 22, 40, 9, 41, 23, 42, 13, 43, 24, 44, 24, 45, 8
Offset: 1

Views

Author

Antti Karttunen, Jan 03 2015

Keywords

Examples

			a(2) = 1, because 2 sits nearest to the top-left corner of the array A246278.
		

Crossrefs

Programs

Formula

a(1) = 0; for n>1: a(n) = A055396(n) + A246277(n) - 1.

A304112 Restricted growth sequence transform of A246277(A064413(n)), related to indices in the prime factorization of EKG sequence.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 17 2018

Keywords

Comments

For all i, j: a(i) = a(j) => A304113(i) = A304113(j).

Crossrefs

Programs

  • PARI
    \\ Needs also code for A064413:
    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)};
    A246277(n) = { if(1==n, 0, while((n%2), n = A064989(n)); (n/2)); };
    Aux304112(n) = A246277(A064413(n));
    write_to_bfile(start_offset,vec,bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }
    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; };
    write_to_bfile(1,rgs_transform(vector(65539,n,Aux304112(n))),"b304112.txt");

A304114 Restricted growth sequence transform of A246277(A098550(n)), related to indices in the prime factorization of Yellowstone permutation.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 17 2018

Keywords

Crossrefs

Cf. also A304112.

Programs

  • PARI
    \\ Needs also code for A098550:
    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)};
    A246277(n) = { if(1==n, 0, while((n%2), n = A064989(n)); (n/2)); };
    Aux304114(n) = A246277(A098550(n));
    write_to_bfile(start_offset,vec,bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }
    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; };
    write_to_bfile(1,rgs_transform(vector(65539,n,Aux304114(n))),"b304114.txt");

Formula

For all i, j: a(i) = a(j) => A304115(i) = A304115(j).

A304742 Restricted growth sequence transform of A246277(A280866(n)).

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 18 2018

Keywords

Comments

For all i, j: a(i) = a(j) => A304743(i) = A304743(j).

Crossrefs

Programs

  • PARI
    \\ Needs also code from A280866:
    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)};
    A246277(n) = { if(1==n, 0, while((n%2), n = A064989(n)); (n/2)); };
    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; };
    v304742 = rgs_transform(vector(65539,n,A246277(A280866(n))));
    A304742(n) = v304742[n];

A319339 Filter sequence combining A081373(n) with A246277(n).

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Sep 24 2018

Keywords

Comments

Restricted growth sequence transform of ordered pair [A081373(n), A246277(n)].

Crossrefs

Programs

  • PARI
    up_to = 65537;
    ordinal_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), pt); for(i=1, length(invec), if(mapisdefined(om,invec[i]), pt = mapget(om, invec[i]), pt = 0); outvec[i] = (1+pt); mapput(om,invec[i],(1+pt))); outvec; };
    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; };
    v081373 = ordinal_transform(vector(up_to,n,eulerphi(n)));
    A081373(n) = v081373[n];
    A246277(n) = if(1==n, 0, my(f = factor(n), k = primepi(f[1,1])-1); for (i=1, #f~, f[i,1] = prime(primepi(f[i,1])-k)); factorback(f)/2);
    v319339 = rgs_transform(vector(up_to,n,[A081373(n),A246277(n)]));
    A319339(n) = v319339[n];

A329371 Dirichlet convolution of the identity function with A246277.

Original entry on oeis.org

0, 1, 1, 4, 1, 8, 1, 12, 5, 12, 1, 28, 1, 16, 11, 32, 1, 37, 1, 44, 15, 24, 1, 80, 7, 28, 19, 60, 1, 82, 1, 80, 21, 36, 15, 128, 1, 40, 27, 128, 1, 114, 1, 92, 49, 48, 1, 208, 9, 89, 33, 108, 1, 146, 21, 176, 39, 60, 1, 284, 1, 64, 69, 192, 25, 174, 1, 140, 45, 170, 1, 364, 1, 76, 70, 156, 21, 210, 1, 336, 65, 84, 1, 396, 33, 88, 55, 272, 1, 368, 25, 188, 63
Offset: 1

Views

Author

Antti Karttunen, Nov 12 2019

Keywords

Crossrefs

Programs

  • PARI
    A246277(n) = if(1==n, 0, my(f = factor(n), k = primepi(f[1,1])-1); for (i=1, #f~, f[i,1] = prime(primepi(f[i,1])-k)); factorback(f)/2);
    A329371(n) = sumdiv(n,d,(n/d)*A246277(d));

Formula

a(n) = Sum_{d|n} d * A246277(n/d).

A373983 Lexicographically earliest infinite sequence such that a(i) = a(j) = A246277(A324886(i)) = A246277(A324886(j)) and A278226(A328768(i)) = A278226(A328768(j)), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jun 25 2024

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A246277(A276086(A108951(n))), A046523(A276086(A328768(n)))].
For all i, j >= 1:
A305800(i) = A305800(j) => a(i) = a(j),
a(i) = a(j) => A329345(i) = A329345(j) => A329045(i) = A329045(j),
a(i) = a(j) => A373982(i) = A373982(j) => A328771(i) = A328771(j).
It is hard to say for sure which graphical features in the scatter plot have their provenance in A373982, and which ones in A329345.

Crossrefs

Programs

  • PARI
    up_to = 100000;
    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; };
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };
    A108951(n) = { my(f=factor(n)); prod(i=1, #f~,  prod(i=1, primepi(f[i, 1]), prime(i))^f[i, 2]); };
    A246277(n) = if(1==n, 0, my(f = factor(n), k = primepi(f[1,1])-1); for (i=1, #f~, f[i,1] = prime(primepi(f[i,1])-k)); factorback(f)/2);
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A002110(n) = prod(i=1,n,prime(i));
    A328768(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]*A002110(primepi(f[i,1])-1)/f[i, 1]));
    Aux373983(n) = [A246277(A276086(A108951(n))), A046523(A276086(A328768(n)))];
    v373983 = rgs_transform(vector(up_to, n, Aux373983(n)));
    A373983(n) = v373983[n];

A286457 Compound filter: a(n) = P(A078898(n), A246277(n)), with a(1) = 0, where P(n,k) is sequence A000027 used as a pairing function.

Original entry on oeis.org

0, 1, 1, 5, 1, 13, 1, 25, 5, 41, 1, 61, 1, 85, 13, 113, 1, 145, 1, 181, 32, 221, 1, 265, 5, 313, 33, 365, 1, 421, 1, 481, 72, 545, 13, 613, 1, 685, 143, 761, 1, 841, 1, 925, 86, 1013, 1, 1105, 5, 1201, 219, 1301, 1, 1405, 32, 1513, 335, 1625, 1, 1741, 1, 1861, 201, 1985, 60, 2113, 1, 2245, 447, 2381, 1, 2521, 1, 2665, 223, 2813, 13, 2965, 1, 3121, 224, 3281
Offset: 1

Views

Author

Antti Karttunen, May 14 2017

Keywords

Crossrefs

Programs

Formula

a(1) = 0 and for n > 1, a(n) = (1/2)*(2 + ((A078898(n)+A246277(n))^2) - A078898(n) - 3*A246277(n)).

A304731 Restricted growth sequence transform of A246277(A304531(n)).

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 19 2018

Keywords

Comments

For all i, j: a(i) = a(j) => A304732(i) = A304732(j).

Crossrefs

Differs from related A304728 for the first time at n=66, where a(66) = 18, while A304728(66) = 50.
Cf. also A304535, A304732.

Programs

  • PARI
    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; };
    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)};
    A246277(n) = { if(1==n, 0, while((n%2), n = A064989(n)); (n/2)); };
    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; };
    v304731 = rgs_transform(vector(76503,n,A246277(A304531(n)))); \\ Needs also code from A304531
    A304731(n) = v304731[n];

A337202 a(n) = 2*A246277(A047802(n)).

Original entry on oeis.org

12, 120, 19399380, 195534950863140268380, 1678409980907129617069656971232406858049983380, 1193774258350145889842491509271710921616406416330926349273223856572483463433620
Offset: 0

Views

Author

Antti Karttunen, Aug 19 2020

Keywords

Comments

Question: Are there any duplicate terms, not necessarily consecutive? That is, are there two or more terms of A047802 that occur in the same column of array A246278?

Crossrefs

Programs

  • PARI
    A246277(n) = if(1==n, 0, my(f = factor(n), k = primepi(f[1,1])-1); for (i=1, #f~, f[i,1] = prime(primepi(f[i,1])-k)); factorback(f)/2);
    A337202(n) = 2*A246277(A047802(n));

Formula

For all n >= 0, a(n) >= A336389(1+n).
Previous Showing 21-30 of 86 results. Next