A329348 The least significant nonzero digit in the primorial base expansion of primorial inflation of n, A108951(n).

1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 4, 1, 2, 6, 2, 1, 2, 1, 4, 6, 2, 1, 3, 2, 2, 1, 4, 1, 5, 1, 1, 6, 2, 8, 4, 1, 2, 6, 1, 1, 1, 1, 4, 1, 2, 1, 1, 1, 4, 6, 4, 1, 2, 4, 8, 6, 2, 1, 3, 1, 2, 3, 2, 13, 12, 1, 4, 6, 5, 1, 3, 1, 2, 5, 4, 2, 12, 1, 2, 1, 2, 1, 2, 11, 2, 6, 8, 1, 2, 6, 4, 6, 2, 7, 2, 1, 2, 10, 1, 1, 12, 1, 8, 4

Offset

1,4

Comments

Number of occurrences of the least primorial present in the greedy sum of primorials adding to A108951(n).

The greedy sum is also the sum with the minimal number of primorials, used for example in the primorial base representation.

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to primorial base

Index entries for sequences related to primorial numbers

Formula

a(n) = A067029(A324886(n)) = A276088(A108951(n)).

a(n) <= A324888(n).

From Antti Karttunen, Jan 15-17 2020: (Start)

a(n) = A331188(n) mod A117366(n).

a(n) = A001511(A246277(A324886(n))).

(End)

Example

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 least primorial in the sum is 3, we have a(24) = 3.

Prog

(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
A276088(n) = { my(e=0, p=2); while(n && !(e=(n%p)), n = n/p; p = nextprime(1+p)); (e); };
A329348(n) = A276088(A108951(n));
(PARI)
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));
A067029(n) = if(1==n, 0, factor(n)[1, 2]); \\ From A067029
A329348(n) = A067029(A324886(n));
(PARI)
A002110(n) = prod(i=1, n, prime(i));
A329348(n) = if(1==n, n, my(f=factor(n), p=nextprime(1+vecmax(f[, 1]))); prod(i=1, #f~, A002110(primepi(f[i, 1]))^(f[i, 2]-(#f~==i)))%p); \\ Antti Karttunen, Jan 15 2020

Crossrefs

Cf. A002110, A034386, A067029, A108951, A117366, A276086, A276088, A324886, A324888, A329040, A329345, A329343, A329344, A329349, A331188, A331289, A331290, A331291.

Cf. also A331292 (the next digit to left of this one), A331293.

Sequence in context: A175327 A101211 A329349 * A329344 A081652 A302790

Adjacent sequences: A329345 A329346 A329347 * A329349 A329350 A329351

Keyword

nonn

Author

Antti Karttunen, Nov 11 2019

Extensions

Name changed by Antti Karttunen, Jan 17 2020

Status

approved