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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A344591 Numbers k such that the primorial inflation of k is a sum of distinct primorial numbers.

Original entry on oeis.org

1, 2, 3, 5, 7, 8, 9, 11, 13, 17, 19, 23, 27, 29, 31, 32, 37, 40, 41, 42, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 115, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 228, 229, 233, 239, 241, 251, 252, 257, 263, 269, 271, 277, 281, 283, 293
Offset: 1

Views

Author

Antti Karttunen, May 26 2021

Keywords

Comments

Numbers k such that A108951(k) is in A276156.

Examples

			A108951(40) = 240 and 240 is in A276156 because 240 = A002110(4) + A002110(3) = 210 + 30, therefore 40 is included in this sequence.
		

Crossrefs

Positions of ones in A329344, in A344592 and in A344593.
Positions of squarefree terms in A324886.
Union of A008578 and A351959.
Cf. A002110, A108951, A276156, A351957 (characteristic function).
Cf. also A351958.

Extensions

Name changed by Antti Karttunen, Apr 04 2022

A345941 a(n) = gcd(n, A329044(n)).

Original entry on oeis.org

1, 2, 3, 4, 5, 3, 7, 2, 3, 5, 11, 3, 13, 7, 5, 4, 17, 9, 19, 5, 7, 11, 23, 3, 25, 13, 3, 7, 29, 5, 31, 2, 11, 17, 7, 9, 37, 19, 13, 5, 41, 7, 43, 11, 5, 23, 47, 3, 7, 25, 17, 13, 53, 9, 11, 7, 19, 29, 59, 5, 61, 31, 7, 4, 13, 11, 67, 17, 23, 7, 71, 9, 73, 37, 25, 19, 11, 13, 79, 5, 3, 41, 83, 7, 17, 43, 29, 11, 89
Offset: 1

Views

Author

Antti Karttunen, Jul 03 2021

Keywords

Comments

Only powers of primes (A000961) occur as terms. A346087 gives the exponents. - Antti Karttunen, Jul 07 2021

Crossrefs

Programs

Formula

a(n) = gcd(n, A329044(n)).
a(n) = n / A345942(n).
a(n) = A329044(n) / A345943(n).
a(p) = p for all primes p.
From Antti Karttunen, Jul 07 2021: (Start)
a(n) = A006530(n)^A346087(n) = A006530(n)^min(A071178(n), A329348(n)).
a(n) = gcd(n, A346097(n)).
A006530(a(n)) = A020639(A329044(n)) = A006530(n).
(End)

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).

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).

A329618 a(n) = gcd(A001222(n), A324888(n)), where A324888(n) is the minimal number of primorials (A002110) that add to A108951(n).

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 1, 1, 2, 2, 1, 1, 1, 2, 2, 4, 1, 1, 1, 1, 2, 2, 1, 4, 2, 2, 1, 1, 1, 3, 1, 1, 2, 2, 2, 4, 1, 2, 2, 2, 1, 1, 1, 1, 3, 2, 1, 1, 2, 3, 2, 1, 1, 4, 2, 4, 2, 2, 1, 2, 1, 2, 3, 2, 2, 3, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 4, 2, 1, 4, 2, 2, 2, 4, 1, 4, 2, 1, 2, 2, 2, 2, 1, 1, 3, 4, 1, 3, 1, 4, 1
Offset: 1

Views

Author

Antti Karttunen, Nov 18 2019

Keywords

Crossrefs

Programs

  • Mathematica
    With[{b = Reverse@ Prime@ Range@ 120}, Array[GCD[PrimeOmega@ #1, Total@ IntegerDigits[#2, 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
    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));
    A329618(n) = gcd(bigomega(n), bigomega(A324886(n)));

Formula

a(n) = gcd(A001222(n), A324888(n)) = gcd(A001222(n), A001222(A324886(n))).

A331292 The next more significant digit after A329348(n) in the primorial base expansion of A108951(n).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 1, 4, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 4, 0, 0, 0, 1, 0, 1, 0, 0, 5, 0, 0, 3, 6, 8, 0, 0, 0, 0, 2, 0, 0, 0, 0, 3, 0, 0, 3, 0, 1, 0, 0, 0, 0, 5, 0, 2, 0, 0, 3, 0, 16, 0, 0, 2, 1, 0, 0, 2, 1, 0, 0, 0, 0, 10, 12, 0, 0, 0, 1, 6, 0, 12, 2, 6, 0, 0, 0, 0, 3
Offset: 1

Views

Author

Antti Karttunen, Jan 17 2020

Keywords

Crossrefs

Programs

Formula

a(n) = A007949(A246277(A324886(n))).
a(n) = A331293(n) modulo A000040(2+A061395(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];

A346099 a(n) = gcd(n, A346098(n)).

Original entry on oeis.org

1, 2, 3, 4, 5, 3, 7, 1, 1, 5, 11, 3, 13, 7, 5, 1, 17, 1, 19, 5, 7, 11, 23, 3, 1, 13, 3, 7, 29, 5, 31, 2, 11, 17, 7, 1, 37, 19, 13, 1, 41, 1, 43, 11, 1, 23, 47, 1, 1, 1, 17, 13, 53, 9, 11, 7, 19, 29, 59, 1, 61, 31, 1, 4, 13, 11, 67, 17, 23, 1, 71, 3, 73, 37, 25, 19, 1, 13, 79, 1, 1, 41, 83, 1, 17, 43, 29, 11, 89
Offset: 1

Views

Author

Antti Karttunen, Jul 07 2021

Keywords

Comments

Only powers of primes (A000961) occur as terms. A346100 lists the exponents.

Crossrefs

Cf. A346090 (positions of ones).

Programs

Formula

a(n) = gcd(n, A346098(n)) = gcd(n, A064989(A319626(A324886(n)))).
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