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 1-5 of 5 results.

A336159 Lexicographically earliest infinite sequence such that a(i) = a(j) => A278222(i) = A278222(j) and A336158(i) = A336158(j), for all i, j >= 1.

Original entry on oeis.org

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

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Author

Antti Karttunen, Jul 11 2020

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A278222(n), A336158(n)], i.e., of the ordered pair [A046523(A005940(1+n)), A046523(A000265(n))].
For all i, j: A324400(i) = A324400(j) => A003602(i) = A003602(j) => a(i) = a(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; };
    A000265(n) = (n>>valuation(n,2));
    A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
    A278222(n) = A046523(A005940(1+n));
    A336158(n) = A046523(A000265(n));
    Aux336159(n) = [A278222(n), A336158(n)];
    v336159 = rgs_transform(vector(up_to, n, Aux336159(n)));
    A336159(n) = v336159[n];

A336146 Lexicographically earliest infinite sequence such that a(i) = a(j) => A000035(i) = A000035(j) and A000265(i) = A000265(j), for all i, j >= 1.

Original entry on oeis.org

1, 2, 3, 2, 4, 5, 6, 2, 7, 8, 9, 5, 10, 11, 12, 2, 13, 14, 15, 8, 16, 17, 18, 5, 19, 20, 21, 11, 22, 23, 24, 2, 25, 26, 27, 14, 28, 29, 30, 8, 31, 32, 33, 17, 34, 35, 36, 5, 37, 38, 39, 20, 40, 41, 42, 11, 43, 44, 45, 23, 46, 47, 48, 2, 49, 50, 51, 26, 52, 53, 54, 14, 55, 56, 57, 29, 58, 59, 60, 8, 61, 62, 63, 32, 64, 65, 66, 17, 67, 68, 69, 35, 70, 71, 72, 5, 73, 74, 75, 38, 76, 77, 78, 20, 79
Offset: 1

Views

Author

Antti Karttunen, Jul 12 2020

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A000035(n), A000265(n)] (parity and the odd part of n), or equally, of the ordered pair [A000265(n), A278221(n)].
For all i, j:
A324400(i) = A324400(j) => a(i) = a(j),
a(i) = a(j) => A336126(i) = A336126(j),
a(i) = a(j) => A336147(i) = A336147(j),
a(i) = a(j) => A336148(i) = A336148(j),
a(i) = a(j) => A336149(i) = A336149(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; };
    A000035(n) = (n%2);
    A000265(n) = (n>>valuation(n,2));
    Aux336146(n) = [A000035(n), A000265(n)];
    v336146 = rgs_transform(vector(up_to, n, Aux336146(n)));
    A336146(n) = v336146[n];

A336148 Lexicographically earliest infinite sequence such that a(i) = a(j) => A278221(i) = A278221(j) and A336158(i) = A336158(j), for all i, j >= 1.

Original entry on oeis.org

1, 2, 3, 2, 4, 5, 6, 2, 7, 8, 9, 5, 10, 11, 12, 2, 13, 14, 15, 8, 16, 17, 18, 5, 19, 20, 21, 11, 22, 23, 24, 2, 25, 26, 27, 14, 28, 29, 30, 8, 31, 32, 33, 17, 34, 35, 36, 5, 37, 38, 39, 20, 40, 41, 25, 11, 42, 43, 44, 23, 45, 46, 47, 2, 48, 49, 50, 26, 51, 32, 52, 14, 53, 54, 34, 29, 55, 56, 57, 8, 58, 59, 60, 32, 61, 62, 63, 17, 64, 65, 30, 35, 66, 67, 68, 5, 69, 70, 71, 38, 72, 73, 74, 20, 75
Offset: 1

Views

Author

Antti Karttunen, Jul 12 2020

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A278221(n), A336158(n)], i.e., of the ordered pair [A046523(A122111(n)), A046523(A000265(n))].
For all i, j: A324400(i) = A324400(j) => A336146(i) = A336146(j) => a(i) = a(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; };
    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)));
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
    A278221(n) = A046523(A122111(n));
    A000265(n) = (n>>valuation(n,2));
    A336158(n) = A046523(A000265(n));
    Aux336148(n) = [A278221(n),A336158(n)];
    v336148 = rgs_transform(vector(up_to, n, Aux336148(n)));
    A336148(n) = v336148[n];

A035531 a(n) = A000120(n) + A001221(n) - 1.

Original entry on oeis.org

0, 1, 2, 1, 2, 3, 3, 1, 2, 3, 3, 3, 3, 4, 5, 1, 2, 3, 3, 3, 4, 4, 4, 3, 3, 4, 4, 4, 4, 6, 5, 1, 3, 3, 4, 3, 3, 4, 5, 3, 3, 5, 4, 4, 5, 5, 5, 3, 3, 4, 5, 4, 4, 5, 6, 4, 5, 5, 5, 6, 5, 6, 7, 1, 3, 4, 3, 3, 4, 5, 4, 3, 3, 4, 5, 4, 5, 6, 5, 3, 3, 4, 4, 5, 5, 5, 6, 4, 4, 6, 6, 5, 6, 6, 7, 3, 3, 4, 5, 4, 4, 6, 5, 4, 6, 5, 5, 5, 5, 7, 7
Offset: 1

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Author

Keywords

Crossrefs

Cf. also A336149.

Programs

  • Maple
    A035531 := proc(n)
        A000120(n)+A001221(n)-1 ;
    end proc:
    seq(A035531(n),n=1..100) ; # R. J. Mathar, Mar 12 2018
  • Mathematica
    Table[DigitCount[n, 2, 1] + PrimeNu[n] - 1, {n, 1, 100}] (* G. C. Greubel, Apr 24 2017 *)
  • PARI
    a(n) = hammingweight(n) + omega(n) - 1; \\ Michel Marcus, Apr 25 2017
    
  • Python
    from sympy import primefactors
    def a(n): return 0 if n<2 else bin(n)[2:].count("1") + len(primefactors(n)) - 1 # Indranil Ghosh, Apr 25 2017

Formula

G.f.: Sum a(n) x^n = Sum A000120(p)*x^p/(1-x^p), p = prime.

Extensions

More terms from David W. Wilson.

A336147 Lexicographically earliest infinite sequence such that a(i) = a(j) => A020639(i) = A020639(j) and A278221(i) = A278221(j), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jul 12 2020

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A020639(n), A278221(n)].
For all i, j:
A324400(i) = A324400(j) => A336146(i) = A336146(j) => a(i) = a(j),
a(i) = a(j) => A243055(i) = A243055(j),
a(i) = a(j) => A336150(i) = A336150(j).

Crossrefs

First differs from A322590 at a(70) = 28 instead of 44.

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; };
    A020639(n) = if(1==n, n, factor(n)[1, 1]);
    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)));
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
    A278221(n) = A046523(A122111(n));
    Aux336147(n) = [A020639(n),A278221(n)];
    v336147 = rgs_transform(vector(up_to, n, Aux336147(n)));
    A336147(n) = v336147[n];
Showing 1-5 of 5 results.