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A259394 Primes of the form (sum of the digits of k to consecutive powers starting at 1) + k, ordered by k (duplicates allowed). 0
2, 11, 13, 17, 23, 31, 41, 53, 67, 83, 101, 53, 89, 61, 67, 97, 127, 79, 83, 89, 97, 107, 149, 167, 101, 101, 103, 131, 839, 127, 193, 347, 863, 157, 167, 379, 677, 197, 199, 227, 419, 547, 313, 467, 983, 223, 281, 563, 733, 241, 251, 271, 463, 761, 277, 307, 499, 797, 331, 389 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Matematico Fresnillense, Bella Curiosidad Matematica
EXAMPLE
For 10<=n<=19,
10 -> 1^1 + 0^2 + 10 = 11
11 -> 1^1 + 1^2 + 11 = 13
12 -> 1^1 + 2^2 + 12 = 17
13 -> 1^1 + 3^2 + 13 = 23
14 -> 1^1 + 4^2 + 14 = 31
15 -> 1^1 + 5^2 + 15 = 41
16 -> 1^1 + 6^2 + 16 = 53
17 -> 1^1 + 7^2 + 17 = 67
18 -> 1^1 + 8^2 + 18 = 83
19 -> 1^1 + 9^2 + 19 = 101
MAPLE
f:= proc(k) local L, j;
L:= convert(k, base, 10);
add(L[-i]^i, i=1..nops(L))+k
end proc:
select(isprime, map(f, [$1..1000])); # Robert Israel, Jul 13 2015
MATHEMATICA
f[n_] := Block[{d = IntegerDigits[n], p},
p = n + Total[d^Range[Length[d]]]; If[PrimeQ@p, p, {}]];
Array[f, 300] // Flatten (* Robert G. Wilson v, Jul 12 2015 *)
PROG
(PARI) f(n)={my(v=digits(n), k=#v, i, j=n); for(i=1, k, j+=v[i]^i); return(j); }
main(size)={my(v=vector(size), i, t=1); for(i=1, size, while(!isprime(f(t)), t++); v[i]=f(t); t++); v; } /* Anders Hellström, Jul 13 2015 */
CROSSREFS
Sequence in context: A338976 A160950 A141168 * A079132 A184802 A023257
KEYWORD
nonn,base
AUTHOR
STATUS
approved

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Last modified March 29 07:27 EDT 2024. Contains 371265 sequences. (Running on oeis4.)