A171444 Sum of three consecutive reversed primes.

10, 15, 23, 49, 113, 193, 194, 215, 137, 178, 100, 121, 122, 143, 204, 146, 187, 109, 130, 151, 172, 233, 215, 278, 481, 1103, 1903, 1913, 1933, 1163, 1583, 1793, 2603, 2023, 1843, 1263, 1873, 1493, 2103, 1523, 1343, 763, 1373, 2173, 1894, 1425

Offset: 1

Author

Vincenzo Librandi, Dec 09 2009

Keywords

• nonn
• base

Examples

			(from primes 11, 13, and 17): 11 + 31 + 71 = 113;
(from primes 13, 17, and 19): 31 + 71 + 91 = 193;
(from primes 173, 179, and 181): 371 + 971 + 181 = 1523.
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A034961, A004087.

Programs

Mathematica

r[n_] := FromDigits[Reverse[IntegerDigits[n]]]; Table[r[Prime[n]] + r[Prime[n+1]] + r[Prime[n+2]], {n, 50}]

Formula

a(n) = r(p(n)) + r(p(n+1)) + r(p(n+2)) where p(n) is the n-th prime number and r(n) is the number obtained by the reversal of the digits of n (e.g., r(1230) = 321).

Extensions

More terms from Matthew Conroy, Dec 28 2010