Francesco Vissani - cp's OEIS frontend

User: Francesco Vissani

Francesco Vissani has authored 2 sequences.

A333128 Ending position of the first occurrence of n in the decimal expansion of Pi.

33, 2, 7, 1, 3, 5, 8, 14, 12, 6, 51, 96, 150, 112, 3, 5, 42, 97, 426, 39, 55, 95, 137, 18, 294, 91, 8, 30, 35, 188, 66, 2, 17, 26, 88, 11, 287, 48, 19, 45, 72, 4, 94, 25, 61, 62, 21, 121, 89, 59, 33, 50, 174, 10, 193, 132, 212, 406, 12, 6, 129, 221, 22, 314

Offset: 0

Francesco Vissani, Apr 08 2020

Variant of A032445, considering the position of the least-significant digit of n in the decimal expansion of Pi (A000796).

Cf. A000796, A004216, A032445.

n = 1000;
intPi = Ceiling[N[Pi, n]*10^(n-1)];
piString = ToString[intPi];
Table[StringPosition[piString, ToString[n]][[1, 2]] , {n, 0, 70}]

a(n) = A032445(n) for n=0..9.
a(n) = 1 + A032445(n) for n = 10..99.
a(n) = A004216(n) + A032445(n).

A308596 a(n) is the product of the prime(n) smallest primes other than prime(n).

Original entry on oeis.org

15, 70, 6006, 1385670, 674612557710, 1006366256282310, 6899316550553351234310, 29365306848773629524600810, 1033423560710676120463066852232970, 1090001884152331303039489872122195258388782310

Offset: 1

Francesco Vissani, Jun 09 2019

nonn

			  |    p =   |    a(n) = product of p smallest
n | prime(n) |            primes other than p
--+----------+--------------------------------------------
1 |     2    |      15 =     3 * 5
2 |     3    |      70 = 2     * 5 * 7
3 |     5    |    6006 = 2 * 3     * 7 * 11 * 13
4 |     7    | 1385670 = 2 * 3 * 5     * 11 * 13 * 17 * 19

Cf. A002110, A306237.

Table[a[i]=Product[Prime[j],{j,1,Prime[i]+1}]/Prime[i],{i,10}]

a(n) = prime(prime(n)+1)#/prime(n).

cp's OEIS Frontend

User: Francesco Vissani

A333128 Ending position of the first occurrence of n in the decimal expansion of Pi.

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