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.

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

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%I A329348 #32 Jan 17 2020 23:37:24
%S A329348 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,
%T A329348 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,
%U A329348 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
%N A329348 The least significant nonzero digit in the primorial base expansion of primorial inflation of n, A108951(n).
%C A329348 Number of occurrences of the least primorial present in the greedy sum of primorials adding to A108951(n).
%C A329348 The greedy sum is also the sum with the minimal number of primorials, used for example in the primorial base representation.
%H A329348 Antti Karttunen, <a href="/A329348/b329348.txt">Table of n, a(n) for n = 1..65537</a>
%H A329348 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%H A329348 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%H A329348 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a>
%F A329348 a(n) = A067029(A324886(n)) = A276088(A108951(n)).
%F A329348 a(n) <= A324888(n).
%F A329348 From _Antti Karttunen_, Jan 15-17 2020: (Start)
%F A329348 a(n) = A331188(n) mod A117366(n).
%F A329348 a(n) = A001511(A246277(A324886(n))).
%F A329348 (End)
%e A329348 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.
%o A329348 (PARI)
%o A329348 A034386(n) = prod(i=1, primepi(n), prime(i));
%o A329348 A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) };  \\ From A108951
%o A329348 A276088(n) = { my(e=0, p=2); while(n && !(e=(n%p)), n = n/p; p = nextprime(1+p)); (e); };
%o A329348 A329348(n) = A276088(A108951(n));
%o A329348 (PARI)
%o A329348 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
%o A329348 A324886(n) = A276086(A108951(n));
%o A329348 A067029(n) = if(1==n, 0, factor(n)[1, 2]); \\ From A067029
%o A329348 A329348(n) = A067029(A324886(n));
%o A329348 (PARI)
%o A329348 A002110(n) = prod(i=1, n, prime(i));
%o A329348 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
%Y A329348 Cf. A002110, A034386, A067029, A108951, A117366, A276086, A276088, A324886, A324888, A329040, A329345, A329343, A329344, A329349, A331188, A331289, A331290, A331291.
%Y A329348 Cf. also A331292 (the next digit to left of this one), A331293.
%K A329348 nonn
%O A329348 1,4
%A A329348 _Antti Karttunen_, Nov 11 2019
%E A329348 Name changed by _Antti Karttunen_, Jan 17 2020