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

1,1

Links

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

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).

Example

(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.

Mathematica

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

Crossrefs

Cf. A034961, A004087.

Sequence in context: A050200 A034961 A207637 * A227371 A057990 A272779

Adjacent sequences: A171441 A171442 A171443 * A171445 A171446 A171447

Keyword

nonn,base

Author

Vincenzo Librandi, Dec 09 2009

Extensions

More terms from Matthew Conroy, Dec 28 2010

Status

approved