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 21-24 of 24 results.

A133977 Home primes whose homeliness is greater than 11.

Original entry on oeis.org

378997, 747521, 777643, 2333797, 2337397, 2337691, 3127979, 3127997, 3136607, 3173761, 3373547, 3373907, 3374729, 3377999, 3378317, 3379829, 3574657, 3639997, 3733967, 3746507, 3759263, 3774161, 3777419, 3784463, 3789293
Offset: 1

Views

Author

Robert G. Wilson v, Sep 30 2007

Keywords

Comments

Number of terms < 10^n: 0, 0, 0, 0, 0, 3, 36, ....

Crossrefs

Cf. A037274, A118756, A133957, A133959, A133961, A133963, A133965, A133967, A133969, A133971, A133973, A133975, A133979.

Programs

  • Mathematica
    lst = {}; f[n_] := FromDigits@ Flatten[ IntegerDigits@ Table[ #[[1]], {#[[2]]}] & /@ FactorInteger@n, 2]; h[n_] := NestWhileList[f@# &, n, !PrimeQ@# &, 1, 28]; Do[p = h[n][[ -1]]; If[ PrimeQ@p && p < 10^7 && p != n, Print[{n, p}]; AppendTo[lst, p]], {n, 2, 1000}];
d = 12 - 2; lsu = {}; Do[ If[ lst[[n]] == lst[[n + d]], AppendTo[ lsu, lst[[n]] ]], {n, 188004 - d - 1}]; Take[ Union@ lsu, 30]

A133978 Home primes whose homeliness is 12.

Original entry on oeis.org

378997, 777643, 3127979, 3127997, 3136607, 3173761, 3374729, 3377999, 3759263, 3774161, 3791387, 3943967, 7342469, 7521641, 7540541, 7767709
Offset: 1

Views

Author

Robert G. Wilson v, Sep 30 2007

Keywords

Comments

Number of terms < 10^n: 0, 0, 0, 0, 0, 2, 16, ... .

Crossrefs

Cf. A037274, A118756, A133977, A133956, A133957, A133958, A133960, A133962, A133964, A133966, A133968, A133970, A133972, A133974, A133976.

Programs

  • Mathematica
    lst = {}; f[n_] := FromDigits@ Flatten[ IntegerDigits@ Table[ #[[1]], {#[[2]]}] & /@ FactorInteger@n, 2]; h[n_] := NestWhileList[f@# &, n, !PrimeQ@# &, 1, 28]; Do[p = h[n][[ -1]]; If[ PrimeQ@p && p < 10^7 && p != n, Print[{n, p}]; AppendTo[lst, p]], {n, 2, 1000}];
d = 12 - 2; lsu = {}; Do[ If[ lst[[n]] == lst[[n + d]] && lst[[n - 1]] != lst[[n]] && lst[[n]] != lst[[n + d + 1]], AppendTo[lsu, lst[[n]]]], {n, 188004 - d - 1}]; Take[Union@ lsu, 31]

A133979 Home primes whose homeliness is greater than 12.

Original entry on oeis.org

747521, 2333797, 2337397, 2337691, 3373547, 3373907, 3378317, 3379829, 3574657, 3639997, 3733967, 3746507, 3777419, 3784463, 3789293, 3791423, 3795569, 3798923, 4389883, 7548461
Offset: 1

Views

Author

Robert G. Wilson v, Sep 30 2007

Keywords

Comments

Number of terms < 10^n: 0, 0, 0, 0, 0, 1, 20, ....

Crossrefs

Cf. A037274, A118756, A133957, A133959, A133961, A133963, A133965, A133967, A133969, A133971, A133973, A133975, A133977.

Programs

  • Mathematica
    lst = {}; f[n_] := FromDigits@ Flatten[ IntegerDigits@ Table[ #[[1]], {#[[2]]}] & /@ FactorInteger@n, 2]; h[n_] := NestWhileList[f@# &, n, !PrimeQ@# &, 1, 28]; Do[p = h[n][[ -1]]; If[ PrimeQ@p && p < 10^7 && p != n, Print[{n, p}]; AppendTo[lst, p]], {n, 2, 1000}];
d = 13 - 2; lsu = {}; Do[ If[ lst[[n]] == lst[[n + d]], AppendTo[ lsu, lst[[n]] ]], {n, 188004 - d - 1}]; Union@ lsu

A133980 Home primes of semiprimes (A001358).

Original entry on oeis.org

23, 37, 211, 223, 229, 241, 271, 283, 311, 313, 317, 331, 337, 347, 353, 359, 367, 373, 379, 383, 389, 397, 523, 541, 547, 571, 719, 743, 761, 773, 797, 1117, 1123, 1129, 1153, 1171, 1319, 1361, 1367, 1373, 1723, 1741, 1747, 1753, 1759, 1783, 1789, 1931
Offset: 1

Views

Author

Jonathan Vos Post & Robert G. Wilson v, Oct 01 2007, Oct 06 2007

Keywords

Comments

Not the same as A133957.
Number of terms < 10^n: 0, 2, 31, 223, 1638, 11752, 89918, ....

Crossrefs

Cf. A001358, A133955, A133957.

Programs

  • Mathematica
    lst = {}; semiPrimeQ[x_] := Plus @@ Last /@ FactorInteger@x == 2; f[n_] := FromDigits@ Flatten[IntegerDigits@ Table[ #[[1]], {#[[2]]}] & /@ FactorInteger@n, 2]; h[n_] := NestWhileList[ f@# &, n, ! PrimeQ@# &, 1, 6];
Previous Showing 21-24 of 24 results.

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