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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A346109 a(n) = A276085(A108951(A346097(n))), where A346097(n) gives the denominator of the primorial deflation of A276086(A108951(n)).

Original entry on oeis.org

0, 1, 3, 2, 9, 6, 39, 1, 3, 18, 249, 12, 2559, 78, 54, 2, 32589, 6, 543099, 36, 234, 498, 10242789, 9, 96, 5118, 42, 156, 233335659, 45, 6703028889, 10, 1494, 65178, 312, 12, 207263519019, 1086198, 15354, 9, 7628001653829, 39, 311878265181039, 996, 165, 20485578, 13394639596851069, 21, 1284, 192, 195534, 10236, 628284422185342479
Offset: 1

Views

Author

Antti Karttunen, Jul 08 2021

Keywords

Crossrefs

Programs

Formula

a(n) = A346108(n) - A108951(n).

A373985 a(n) = gcd(A108951(n), A373158(n)), where A108951 is fully multiplicative and A373158 is fully additive with a(p) = p# for prime p, where x# is the primorial A034386(x).

Original entry on oeis.org

1, 2, 6, 4, 30, 4, 210, 2, 12, 4, 2310, 2, 30030, 4, 36, 8, 510510, 2, 9699690, 2, 36, 4, 223092870, 12, 60, 4, 18, 2, 6469693230, 2, 200560490130, 2, 12, 4, 60, 16, 7420738134810, 4, 12, 12, 304250263527210, 2, 13082761331670030, 2, 6, 4, 614889782588491410, 2, 420, 2, 36, 2, 32589158477190044730, 4, 180, 24, 36, 4
Offset: 1

Views

Author

Antti Karttunen, Jun 25 2024

Keywords

Crossrefs

Programs

  • PARI
    A373985(n) = { my(f=factor(n),m=1,s=0); for(i=1, #f~, my(x=prod(i=1,primepi(f[i, 1]),prime(i))); s += f[i, 2]*x; m *= x^f[i, 2]); gcd(m,s); };

Formula

a(n) = gcd(A373158(n), A373984(n)).
a(n) = A108951(n) / A373987(n).
For n >= 2, a(n) = A373158(n) / A373986(n).
For n >= 1, a(A000040(n)) = A002110(n).

A329619 Difference between the maximal digit value used when A108951(n) is written in primorial base and its 2-adic valuation.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, -2, -1, 0, 0, 1, 0, 0, 4, -2, 0, -1, 0, 1, 4, 0, 0, -1, 2, 0, -2, 1, 0, 2, 0, -4, 4, 0, 6, 0, 0, 0, 4, -3, 0, -2, 0, 1, 2, 0, 0, -2, 4, 5, 4, 1, 0, -2, 2, 4, 4, 0, 0, -1, 0, 0, 0, -4, 11, 9, 0, 1, 4, 2, 0, -2, 0, 0, 2, 1, 14, 9, 0, -3, 2, 0, 0, -2, 9, 0, 4, 4, 0, 6, 10, 1, 4, 0, 5, 0, 0, 9, 7, 2, 0, 9, 0, 4, 1
Offset: 1

Views

Author

Antti Karttunen, Nov 18 2019

Keywords

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}]] - PrimeOmega[#] &, 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));
    A329619(n) = (A329344(n) - bigomega(n));

Formula

a(n) = A329344(n) - A001222(n).
a(n) = A328114(A108951(n)) - A007814(A108951(n)).
a(p) = 0 for all primes p.

A346093 a(n) = A276085(A328571(A108951(n))).

Original entry on oeis.org

1, 2, 6, 2, 30, 6, 210, 8, 36, 30, 2310, 6, 30030, 210, 30, 8, 510510, 36, 9699690, 30, 210, 2310, 223092870, 36, 240, 30030, 216, 210, 6469693230, 240, 200560490130, 32, 2310, 510510, 2520, 36, 7420738134810, 9699690, 30030, 240, 304250263527210, 2520, 13082761331670030, 2310, 240, 223092870, 614889782588491410, 36, 32550
Offset: 1

Views

Author

Antti Karttunen, Jul 09 2021

Keywords

Crossrefs

Programs

  • PARI
    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]) };
    A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
    A328571(n) = { my(m=1, p=2); while(n, m *= (p^!!(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A346093(n) = A276085(A328571(A108951(n)));

Formula

a(n) = A108951(n) - A346092(n).

A346105 a(n) = A276085(A108951(n)).

Original entry on oeis.org

0, 1, 3, 2, 9, 4, 39, 3, 6, 10, 249, 5, 2559, 40, 12, 4, 32589, 7, 543099, 11, 42, 250, 10242789, 6, 18, 2560, 9, 41, 233335659, 13, 6703028889, 5, 252, 32590, 48, 8, 207263519019, 543100, 2562, 12, 7628001653829, 43, 311878265181039, 251, 15, 10242790, 13394639596851069, 7, 78, 19, 32592, 2561, 628284422185342479, 10, 258, 42
Offset: 1

Views

Author

Antti Karttunen, Jul 08 2021

Keywords

Comments

Additive with a(p^e) = e * A143293(A000720(p)-1), where A143293 is the partial sums of primorials, A002110. (Compare to the formula of A276085).

Crossrefs

Programs

  • PARI
    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]) };
    A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
    A346105(n) = A276085(A108951(n));
    
  • PARI
    A143293(n) = { if(n==0, return(1)); my(P=1, s=1); forprime(p=2, prime(n), s+=P*=p); s; }; \\ This function from A143293
    A346105(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A143293(primepi(f[k, 1])-1)); };

Formula

a(n) = A276085(A108951(n)).

A346106 a(n) = A108951(A346096(n)), where A346096(n) gives the numerator of the primorial deflation of A276086(A108951(n)).

Original entry on oeis.org

2, 6, 30, 36, 210, 900, 2310, 30, 210, 44100, 30030, 810000, 510510, 5336100, 85766121000000, 900, 9699690, 44100, 223092870, 1944810000, 151939915084881000000, 901800900, 6469693230, 189000, 28473963210000, 260620460100, 69300, 28473963210000, 200560490130, 4492511100000, 7420738134810, 1260, 733384949590939374729000000
Offset: 1

Views

Author

Antti Karttunen, Jul 08 2021

Keywords

Crossrefs

Programs

Formula

a(n) = A324886(n) * A346107(n).

A346107 a(n) = A108951(A346097(n)), where A346097(n) gives the denominator of the primorial deflation of A276086(A108951(n)).

Original entry on oeis.org

1, 2, 6, 4, 30, 36, 210, 2, 6, 900, 2310, 1296, 30030, 44100, 729000000, 4, 510510, 36, 9699690, 810000, 85766121000000, 5336100, 223092870, 216, 39690000, 901800900, 1260, 1944810000, 6469693230, 24300000, 200560490130, 60, 151939915084881000000, 260620460100, 3782285936100000000, 1296, 7420738134810, 94083986096100
Offset: 1

Views

Author

Antti Karttunen, Jul 08 2021

Keywords

Crossrefs

Programs

Formula

a(n) = A346106(n) / A324886(n).

A354351 Dirichlet inverse of A108951, primorial inflation of n.

Original entry on oeis.org

1, -2, -6, 0, -30, 12, -210, 0, 0, 60, -2310, 0, -30030, 420, 180, 0, -510510, 0, -9699690, 0, 1260, 4620, -223092870, 0, 0, 60060, 0, 0, -6469693230, -360, -200560490130, 0, 13860, 1021020, 6300, 0, -7420738134810, 19399380, 180180, 0, -304250263527210, -2520, -13082761331670030, 0, 0, 446185740, -614889782588491410
Offset: 1

Views

Author

Antti Karttunen, Jun 05 2022

Keywords

Comments

Multiplicative with a(p^e) = 0 if e > 1, and -A034386(p) otherwise.

Crossrefs

Programs

Formula

a(n) = A008683(n) * A108951(n).
a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, d < n} A108951(n/d) * a(d).
a(n) = A354352(n) - A108951(n).

A329349 Number of occurrences of the largest primorial 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, 1, 4, 2, 1, 4, 1, 1, 1, 1, 6, 2, 2, 4, 1, 2, 6, 1, 1, 1, 1, 4, 5, 2, 1, 3, 1, 8, 6, 4, 1, 2, 2, 8, 6, 2, 1, 3, 1, 2, 3, 2, 1, 12, 1, 4, 6, 5, 1, 1, 1, 2, 2, 4, 16, 12, 1, 2, 6, 2, 1, 2, 1, 2, 6, 8, 1, 10, 12, 4, 6, 2, 1, 6, 1, 2, 2, 1, 1, 12, 1, 8, 1
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 = 21 = 3 * 7, A108951(21) = A034386(3) * A034386(7) = 6 * 210, so the factor of the largest primorial present (210) in the greedy sum is 6 (as 1260 = 210 + 210 + 210 + 210 + 210 + 210), thus a(21) = 6.
For n = 24 = 2^3 * 3, A108951(24) = A034386(2)^3 * A034386(3) = 2^3 * 6 = 48 = 1*30 + 3*6, and as the factor of the largest primorial in the sum is 1, we have a(24) = 1.
		

Crossrefs

Programs

Formula

a(n) = A276153(A108951(n)) = A071178(A324886(n)).
a(n) <= A324888(n).

A329378 Least common multiple of exponents of prime factors of A108951(n), where A108951 is fully multiplicative with a(prime(i)) = prime(i)# = Product_{i=1..i} A000040(i).

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 1, 3, 2, 2, 1, 3, 1, 2, 2, 4, 1, 6, 1, 3, 2, 2, 1, 4, 2, 2, 3, 3, 1, 6, 1, 5, 2, 2, 2, 4, 1, 2, 2, 4, 1, 6, 1, 3, 3, 2, 1, 5, 2, 6, 2, 3, 1, 12, 2, 4, 2, 2, 1, 4, 1, 2, 3, 6, 2, 6, 1, 3, 2, 6, 1, 10, 1, 2, 6, 3, 2, 6, 1, 5, 4, 2, 1, 4, 2, 2, 2, 4, 1, 12, 2, 3, 2, 2, 2, 6, 1, 6, 3, 4, 1, 6, 1, 4, 6
Offset: 1

Views

Author

Antti Karttunen, Nov 17 2019

Keywords

Crossrefs

Differs from related A329617 for the first time at n=36.

Programs

Formula

a(n) = A072411(A108951(n)) = A072411(A329600(n)).
a(n) <= A329617(n) <= A329382(n) <= A329605(n).
a(A019565(n)) = A284002(n).
Previous Showing 21-30 of 158 results. Next