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 1-9 of 9 results.

A329040 Number of distinct primorials in the greedy sum of primorials adding to A108951(n).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 2, 1, 2, 1, 1, 2, 1, 2, 1, 1, 2, 2, 1, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 2, 3, 2, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 1, 1, 2, 2, 2, 1, 1, 1, 1, 2, 1, 3, 1, 1, 3, 1, 2, 1, 1, 2, 3, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 2, 2, 1, 3, 2, 3, 1, 1, 1, 1, 3
Offset: 1

Views

Author

Antti Karttunen, Nov 11 2019

Keywords

Comments

The greedy sum is also the sum with the minimal number of primorials used in the primorial base representation.

Examples

			For n = 18 = 2 * 3^2, A108951(18) = A034386(2) * A034386(3)^2 = 2 * 6^2 = 72 = 2*A002110(3) + 2*A002110(2) = 2*30 + 2*6, and because there occurs only two distinct primorials (30 and 6) in the sum, we have a(18) = 2.
		

Crossrefs

Cf. also A329045, A329046.

Programs

Formula

a(n) = A001221(A324886(n)).
a(n) = A267263(A108951(n)).
a(n) <= A324888(n).

A329044 a(n) = A064989(A324886(n)).

Original entry on oeis.org

1, 2, 3, 4, 5, 9, 7, 6, 15, 25, 11, 81, 13, 49, 15625, 36, 17, 225, 19, 625, 117649, 121, 23, 135, 60025, 169, 21, 2401, 29, 21875, 31, 10, 1771561, 289, 697540921, 50625, 37, 361, 4826809, 35, 41, 77, 43, 14641, 84035, 529, 47, 375, 161212051, 3603000625, 24137569, 28561, 53, 441, 2474329, 5764801, 47045881, 841, 59, 42875, 61, 961
Offset: 1

Views

Author

Antti Karttunen, Nov 08 2019

Keywords

Crossrefs

Programs

  • PARI
    A034386(n) = prod(i=1, primepi(n), prime(i));
    A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) };  \\ From A108951
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A324886(n) = A276086(A108951(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)};
    A329044(n) = A064989(A324886(n));

Formula

a(n) = A064989(A324886(n)).
a(A000040(n)) = A000040(n).

A329345 Lexicographically earliest infinite sequence such that a(i) = a(j) => A246277(A329044(i)) = A246277(A329044(j)) for all i, j.

Original entry on oeis.org

1, 2, 2, 3, 2, 3, 2, 4, 4, 3, 2, 5, 2, 3, 6, 7, 2, 7, 2, 5, 6, 3, 2, 8, 9, 3, 10, 5, 2, 11, 2, 10, 6, 3, 12, 13, 2, 3, 6, 4, 2, 4, 2, 5, 14, 3, 2, 15, 16, 17, 6, 5, 2, 18, 19, 20, 6, 3, 2, 21, 2, 3, 21, 18, 22, 23, 2, 5, 6, 24, 2, 25, 2, 3, 26, 5, 27, 23, 2, 7, 28, 3, 2, 7, 29, 3, 6, 20, 2, 30, 31, 5, 6, 3, 32, 33, 2, 34, 35, 16, 2, 23, 2, 20, 36
Offset: 1

Views

Author

Antti Karttunen, Nov 11 2019

Keywords

Comments

Restricted growth sequence transform of function f(n) = A246277(A329044(n)).
For all i, j:
A305800(i) = A305800(j) => a(i) = a(j),
a(i) = a(j) => A329045(i) = A329045(j),
a(i) = a(j) => A329343(i) = A329343(j),
a(i) = a(j) => A329348(i) = A329348(j),
a(i) = a(j) => A329349(i) = A329349(j).

Crossrefs

Programs

  • PARI
    up_to = 1024;
    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; };
    A034386(n) = prod(i=1, primepi(n), prime(i));
    A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) };  \\ From A108951
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A324886(n) = A276086(A108951(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)};
    A329044(n) = A064989(A324886(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);
    v329345 = rgs_transform(vector(up_to, n, A246277(A329044(n))));
    A329345(n) = v329345[n];

A329344 Number of times most frequent primorial is present in the greedy sum of primorials adding to A108951(n).

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 4, 1, 2, 6, 2, 1, 2, 1, 4, 6, 2, 1, 3, 4, 2, 1, 4, 1, 5, 1, 1, 6, 2, 8, 4, 1, 2, 6, 1, 1, 1, 1, 4, 5, 2, 1, 3, 6, 8, 6, 4, 1, 2, 4, 8, 6, 2, 1, 3, 1, 2, 3, 2, 13, 12, 1, 4, 6, 5, 1, 3, 1, 2, 5, 4, 16, 12, 1, 2, 6, 2, 1, 2, 11, 2, 6, 8, 1, 10, 12, 4, 6, 2, 7, 6, 1, 12, 10, 6, 1, 12, 1, 8, 4
Offset: 1

Views

Author

Antti Karttunen, Nov 11 2019

Keywords

Comments

The greedy sum is also the sum with the minimal number of primorials, used for example in the primorial base representation.

Examples

			For n = 24 = 2^3 * 3, A108951(24) = A034386(2)^3 * A034386(3) = 2^3 * 6 = 48 = 30 + 6 + 6 + 6, and as the most frequent primorial in the sum is 6 = A002110(2), we have a(24) = 3.
		

Crossrefs

Programs

  • Mathematica
    With[{b = Reverse@ Prime@ Range@ 120}, Array[Max@ IntegerDigits[#, MixedRadix[b]] &@ Apply[Times, Map[#1^#2 & @@ # &, FactorInteger[#] /. {p_, e_} /; e > 0 :> {Times @@ Prime@ Range@ PrimePi@ p, e}]] &, 105] ] (* Michael De Vlieger, Nov 18 2019 *)
  • PARI
    A034386(n) = prod(i=1, primepi(n), prime(i));
    A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) };  \\ From A108951
    A328114(n) = { my(s=0, p=2); while(n, s = max(s,(n%p)); n = n\p; p = nextprime(1+p)); (s); };
    A329344(n) = A328114(A108951(n));
    
  • PARI
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A324886(n) = A276086(A108951(n));
    A051903(n) = if((1==n),0,vecmax(factor(n)[, 2]));
    A329344(n) = A051903(A324886(n));

Formula

a(n) = A328114(A108951(n)) = A051903(A324886(n)).

A373982 Lexicographically earliest infinite sequence such that a(i) = a(j) => A278226(A328768(i)) = A278226(A328768(j)), for all i, j >= 0.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jun 25 2024

Keywords

Comments

Restricted growth sequence transform of A278226(A328768(n)).
For all i, j >= 1:
A305800(i) = A305800(j) => A373983(i) = A373983(j) => a(i) = a(j).
For all i, j >= 0: a(i) = a(j) => A328771(i) = A328771(j).

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]); };  \\ From A046523
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A278226(n) = A046523(A276086(n));
    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]));
    v373982 = rgs_transform(vector(1+up_to, n, A278226(A328768(n-1))));
    A373982(n) = v373982[1+n];

A329046 a(n) = A000005(A324886(n)).

Original entry on oeis.org

2, 2, 2, 3, 2, 3, 2, 4, 4, 3, 2, 5, 2, 3, 7, 9, 2, 9, 2, 5, 7, 3, 2, 8, 15, 3, 4, 5, 2, 12, 2, 4, 7, 3, 27, 25, 2, 3, 7, 4, 2, 4, 2, 5, 12, 3, 2, 8, 28, 45, 7, 5, 2, 9, 15, 9, 7, 3, 2, 16, 2, 3, 16, 9, 28, 13, 2, 5, 7, 36, 2, 24, 2, 3, 72, 5, 51, 13, 2, 9, 28, 3, 2, 9, 24, 3, 7, 9, 2, 33, 91, 5, 7, 3, 16, 21, 2, 117, 33, 28, 2, 13, 2, 9, 40
Offset: 1

Views

Author

Antti Karttunen, Nov 08 2019

Keywords

Crossrefs

Programs

Formula

a(n) = A324655(A108951(n)).

A344593 Lexicographically earliest infinite sequence such that a(i) = a(j) => A344592(i) = A344592(j), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 26 2021

Keywords

Comments

Restricted growth sequence transform of A344592, where A344592(n) = A003557(A276086(A108951(n))).
For all i, j: a(i) = a(j) => A329344(i) = A329344(j).

Examples

			Both a(14) = 6 and a(32768) = 6, because A344592(14) = 11 is the sixth distinct value occurring in A344592, and A344592(32768) = A003557(A276086(A108951(32768))) = A003557(A276086(32768)) = A003557(401115) = A003557(3 * 5 * 11^2 * 13 * 17) = 11 also, which is the second time 11 occurs in A344592.
		

Crossrefs

Cf. A003557, A108951, A276086, A324886, A329344, A344591 (positions of ones), A344592.
Cf. also A329045, A329345, A344594.

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; };
    A034386(n) = prod(i=1, primepi(n), prime(i));
    A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) }; \\ From A108951
    A328572(n) = { my(m=1, p=2); while(n, if(n%p, m *= p^((n%p)-1)); n = n\p; p = nextprime(1+p)); (m); };
    A344592(n) = A328572(A108951(n));
    v344593 = rgs_transform(vector(up_to, n, A344592(n)));
    A344593(n) = v344593[n];

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];

A351955 Lexicographically earliest infinite sequence such that a(i) = a(j) => A328571(A108951(i)) = A328571(A108951(j)) for all i, j >= 1.

Original entry on oeis.org

1, 2, 3, 2, 4, 3, 5, 6, 7, 4, 8, 3, 9, 5, 4, 6, 10, 7, 11, 4, 5, 8, 12, 7, 13, 9, 14, 5, 15, 13, 16, 17, 8, 10, 18, 7, 19, 11, 9, 13, 20, 18, 21, 8, 13, 12, 22, 7, 23, 13, 10, 9, 24, 14, 25, 5, 11, 15, 26, 13, 27, 16, 18, 17, 28, 8, 29, 10, 12, 18, 30, 31, 32, 19, 33, 11, 25, 9, 34, 13, 31, 20, 35, 18, 36, 21, 15, 8
Offset: 1

Views

Author

Antti Karttunen, Apr 03 2022

Keywords

Comments

Restricted growth sequence transform of A346091, or equally, of A346093.
For all i, j:
a(i) = a(j) => A006530(i) = A006530(j) [equally, A061395(i) = A061395(j)],
a(i) = a(j) => A329040(i) = A329040(j) => A351956(i) = A351956(j),
a(i) = a(j) => A329343(i) = A329343(j).
Interestingly, some of the rays in the scatter plot appear to be cut to discontinuous segments.

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; };
    A002110(n) = prod(i=1,n,prime(i));
    A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A002110(primepi(f[i, 1]))^f[i, 2]) };
    A328571(n) = { my(m=1, p=2); while(n, m *= (p^!!(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A346091(n) = A328571(A108951(n));
    v351955 = rgs_transform(vector(up_to, n, A346091(n)));
    A351955(n) = v351955[n];
Showing 1-9 of 9 results.