A104463 -id:A104463 - cp's OEIS frontend

A104464 Permutation of natural numbers based on A072756 and A104463.

1, 2, 3, 4, 6, 5, 7, 8, 12, 9, 13, 10, 15, 11, 16, 14, 21, 17, 25, 18, 27, 19, 28, 20, 30, 22, 33, 23, 34, 24, 36, 26, 39, 29, 43, 31, 46, 32, 48, 35, 52, 37, 55, 38, 57, 40, 60, 41, 61, 42, 63, 44, 66, 45, 67, 47, 70, 49, 73, 50, 75, 51, 76, 53, 79, 54, 81, 56, 84, 58, 87, 59

Offset: 1

Clark Kimberling, Mar 08 2005

nonn

Apparently a(n) = A072758(n). - R. J. Mathar, Jul 09 2011

Cf. A072756, A072758, A104463.

Let b(n)=A072756(n) and c(n)=A104463(n). Then this sequence is given by c(1), b(2), c(2), b(3), c(3), b(4), c(4), ...

A104645 Difference between the previous and the next primes to x, where x is the number obtained from concatenation of the first n primes (A019518).

Original entry on oeis.org

10, 6, 20, 24, 24, 60, 18, 48, 100, 48, 156, 74, 88, 68, 42, 126, 366, 106, 186, 136, 228, 104, 30, 246, 52, 218, 814, 58, 536, 174, 90, 924, 180, 298, 120, 330, 96, 508, 504, 60, 762, 588, 330, 138, 552, 726, 452, 634, 660, 354, 534, 1770, 52, 262, 834, 790, 250, 624

Offset: 2

Labos Elemer, Mar 18 2005

			For n=4, concatenate(2,3,5,7) gives 2357. The closest other primes are 2371 and 2351 and their difference is a(4)=20.

Cf. A019518, A074809, A104462, A104463.

Mathematica
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A019518(n)=my(k="");forprime(p=2,prime(n),k=Str(k,p));eval(k)
a(n)=my(k=A019518(n));nextprime(k+1)-precprime(k-1) \\ Charles R Greathouse IV, Apr 28 2010

a(n) = A151800(A019518(n)) - A151799(A019518(n)).

Corrected, extended, and edited by Charles R Greathouse IV, Apr 28 2010

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A104464 Permutation of natural numbers based on A072756 and A104463.

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A104645 Difference between the previous and the next primes to x, where x is the number obtained from concatenation of the first n primes (A019518).

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