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 1-10 of 18 results. Next

A366283 a(n) = gcd(n, A366275(n)), where A366275 is the Cat's tongue permutation.

Original entry on oeis.org

1, 1, 2, 3, 4, 1, 6, 1, 8, 9, 2, 1, 12, 1, 2, 1, 16, 1, 18, 1, 4, 3, 2, 1, 24, 25, 2, 1, 4, 1, 2, 1, 32, 3, 2, 5, 36, 1, 2, 3, 8, 1, 6, 1, 4, 3, 2, 1, 48, 1, 50, 1, 4, 1, 2, 55, 8, 1, 2, 1, 4, 1, 2, 1, 64, 1, 6, 1, 4, 3, 10, 1, 72, 1, 2, 15, 4, 7, 6, 1, 16, 3, 2, 1, 12, 5, 2, 3, 8, 1, 6, 7, 4, 3, 2, 1, 96, 1, 2, 1, 100
Offset: 0

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Crossrefs

Differs from related A364255 for the first time at n=25, where a(25) = 25, while A364255(25) = 5.

Programs

Formula

a(n) = gcd(n,A366282(n)) = gcd(A366275(n),A366282(n)).
a(n) = n / A366284(n) = A366275(n) / A366285(n).

A366282 a(n) = A366275(n) - n, where A366275 is the Cat's tongue permutation.

Original entry on oeis.org

1, 1, 2, 0, 4, 4, 0, -2, 8, 18, 8, 4, 0, 12, -4, -8, 16, 64, 36, 26, 16, 54, 8, -2, 0, 100, 24, 8, -8, 20, -16, -20, 32, 210, 128, 100, 72, 188, 52, 24, 32, 334, 108, 62, 16, 102, -4, -14, 0, 576, 200, 124, 48, 192, 16, 0, -16, 286, 40, 18, -32, 60, -40, -50, 64, 664, 420, 338, 256, 606, 200, 118, 144, 1052, 376
Offset: 0

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Crossrefs

Cf. A057889, A163511, A366275, A366277 (positions of 0's), A366283.
Cf. also A364258.

Programs

A366285 a(n) = A366275(n) / gcd(n, A366275(n)), where A366275 is the Cat's tongue permutation.

Original entry on oeis.org

1, 2, 2, 1, 2, 9, 1, 5, 2, 3, 9, 15, 1, 25, 5, 7, 2, 81, 3, 45, 9, 25, 15, 21, 1, 5, 25, 35, 5, 49, 7, 11, 2, 81, 81, 27, 3, 225, 45, 21, 9, 375, 25, 105, 15, 49, 21, 33, 1, 625, 5, 175, 25, 245, 35, 1, 5, 343, 49, 77, 7, 121, 11, 13, 2, 729, 81, 405, 81, 225, 27, 189, 3, 1125, 225, 21, 45, 63, 21, 99, 9, 625, 375, 525
Offset: 0

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Comments

Denominator of n / A366275(n).

Crossrefs

Cf. A057889, A163511, A366275, A366282, A366283, A366284 (numerators), A366286 (rgs-transform).
Cf. also A364492.

Programs

Formula

a(n) = A366275(n) / A366283(n) = A366275(n) / gcd(n, A366275(n))

A366286 Lexicographically earliest infinite sequence such that a(i) = a(j) => A366285(i) = A366285(j) for all i, j >= 0, where A366285(n) is the denominator of n / A366275(n).

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Comments

Restricted growth sequence transform of A366285.

Crossrefs

Cf. also A365393, A365431 (compare the scatter plots).

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; };
    A366285(n) = { my(u=A366275(n)); (u/gcd(n,u)); }; \\ Uses also the program given in A366275.
    v366286 = rgs_transform(vector(1+up_to,n,A366285(n-1)));
    A366286(n) = v366286[1+n];

A366284 a(n) = n / gcd(n, A366275(n)), where A366275 is the Cat's tongue permutation.

Original entry on oeis.org

0, 1, 1, 1, 1, 5, 1, 7, 1, 1, 5, 11, 1, 13, 7, 15, 1, 17, 1, 19, 5, 7, 11, 23, 1, 1, 13, 27, 7, 29, 15, 31, 1, 11, 17, 7, 1, 37, 19, 13, 5, 41, 7, 43, 11, 15, 23, 47, 1, 49, 1, 51, 13, 53, 27, 1, 7, 57, 29, 59, 15, 61, 31, 63, 1, 65, 11, 67, 17, 23, 7, 71, 1, 73, 37, 5, 19, 11, 13, 79, 5, 27, 41, 83, 7, 17, 43, 29, 11
Offset: 0

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Comments

Numerator of n / A366275(n).

Crossrefs

Cf. also A364491.

Programs

Formula

a(n) = n / A366283(n) = n / gcd(n, A366275(n))

A366277 Fixed points of map n -> A366275(n).

Original entry on oeis.org

3, 6, 12, 24, 48, 55, 96, 110, 192, 220, 384, 440, 768, 880, 1536, 1760, 3072, 3520, 6144, 7040, 12288, 14080, 24576, 28160, 49152, 56320, 98304, 112640, 196608, 225280, 393216, 450560, 786432, 901120, 1572864, 1802240, 3145728, 3604480, 6291456, 7208960, 12582912, 14417920, 25165824, 28835840, 50331648, 57671680
Offset: 1

Views

Author

Antti Karttunen, Oct 06 2023

Keywords

Comments

Equally, fixed points of map n -> A366276(n).
If n is a term, then 2*n is also a term, and vice versa, thus the sequence is wholly determined by its odd terms: 3, 55. Are there any others?

Crossrefs

Cf. A007283 (subsequence), A057889, A163511, A366275, A366276.

Programs

A366278 Perfect powers k such that A052409(k) is equal to A052409(A366275(k)).

Original entry on oeis.org

196, 2116, 2500, 3136, 3844, 9409, 15376, 33856, 37636, 40000, 49729, 50176, 58564, 64516, 148225, 150544, 198916, 229441, 231361, 237169, 246016, 255025, 528529, 541696, 543169, 555025, 592900, 602176, 628849, 640000, 654481, 790321, 795664, 801025, 802816, 917764, 925444, 937024, 948676, 984064, 1020100, 1032256
Offset: 1

Views

Author

Antti Karttunen, Oct 06 2023

Keywords

Comments

Numbers k such that A052409(k) > 1 and A052409(k) = A366281(k).
Conjecture: all terms are squares, and no higher powers occur.

Crossrefs

Subsequence of A001597, and also by conjecture, of A153158 (thus also of A000290).
Cf. also A365805, A365808.

Programs

A366279 The least number with same prime signature as A366275, where A366275(n) = A163511(A057889(n)).

Original entry on oeis.org

1, 2, 4, 2, 8, 4, 6, 2, 16, 8, 12, 6, 12, 4, 6, 2, 32, 16, 24, 12, 36, 12, 30, 6, 24, 8, 12, 6, 12, 4, 6, 2, 64, 32, 48, 24, 72, 36, 60, 12, 72, 24, 60, 30, 60, 12, 30, 6, 48, 16, 24, 12, 36, 12, 30, 6, 24, 8, 12, 6, 12, 4, 6, 2, 128, 64, 96, 48, 144, 72, 120, 24, 216, 72, 180, 60, 180, 36, 60, 12, 144, 48, 120, 60
Offset: 0

Views

Author

Antti Karttunen, Oct 06 2023

Keywords

Crossrefs

Cf. A046523, A057889, A163511, A278531, A366275, A366280 (rgs-transform).
Cf. also A286601, A366261.

Programs

  • PARI
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };
    A030101(n) = if(n<1,0,subst(Polrev(binary(n)),x,2));
    A057889(n) = if(!n,n,A030101(n/(2^valuation(n,2))) * (2^valuation(n, 2)));
    A163511(n) = if(!n, 1, my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(1+p)); n >>= 1); (t*p));
    A366275(n) = A163511(A057889(n));
    A366279(n) = A046523(A366275(n));

Formula

a(n) = A278531(A057889(n)).

A366281 a(n) = largest exponent m for which a representation of the form A366275(n) = k^m exists (for some k). a(0) = 0 by convention.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Oct 06 2023

Keywords

Crossrefs

Cf. A052409, A057889, A365805, A366275, A366278 [where a(n) = A052409(n)].

Programs

Formula

a(n) = A052409(A366275(n)).
a(n) = A365805(A057889(n)).

A366258 Dirichlet inverse of A366283, where A366283(n) = gcd(n, A366275(n)).

Original entry on oeis.org

1, -2, -3, 0, -1, 6, -1, 0, 0, 2, -1, 0, -1, 2, 5, 0, -1, 0, -1, 0, 3, 2, -1, 0, -24, 2, 26, 0, -1, -10, -1, 0, 3, 2, -3, 0, -1, 2, 3, 0, -1, -6, -1, 0, -6, 2, -1, 0, 0, 48, 5, 0, -1, -52, -53, 0, 5, 2, -1, 0, -1, 2, 8, 0, 1, -6, -1, 0, 3, 6, -1, 0, -1, 2, 128, 0, -5, -6, -1, 0, -78, 2, -1, 0, -3, 2, 3, 0, -1, 12
Offset: 1

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Crossrefs

Cf. A366275, A366283, A366259 (rgs-transform).
Cf. also A364257.

Programs

Formula

a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, dA366283(n/d) * a(d).
Showing 1-10 of 18 results. Next