A271628 Primes that are the sum of the digits of the numbers from 1 to n, for some n.

3, 73, 109, 127, 433, 1009, 1117, 1801, 2017, 2089, 2143, 2467, 2503, 2791, 3079, 3331, 3583, 4159, 4519, 4663, 4951, 5437, 5581, 5923, 6121, 6301, 6553, 7039, 7561, 8353, 8623, 8821, 9001, 9199, 9631, 9811, 10837, 11719, 12637, 13177, 13249, 13627, 14401, 15391

Offset

1,1

Links

Paolo P. Lava, Table of n, a(n) for n = 1..10000

Example

The sum of the digits of 1 and 2 is a prime: 1 + 2 = 3.
The sum of the digits of the number from 1 to 16 is a prime: 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 1 + 0 + 1 + 1 + 1 + 2 + 1 + 3 + 1 + 4 + 1 + 5 + 1 + 6 = 73.

Maple

with(numtheory): P:=proc(q) local a, b, c, k, n; a:=0;
for n from 0 to q do b:=0; c:=n; for k from 1 to ilog10(n)+1 do b:=b+(c mod 10); c:=trunc(c/10); od; a:=a+b;
if isprime(a) then print(a); fi; od; end: P(10^6);

Mathematica

Select[Accumulate@ Map[Total@ IntegerDigits@ # &, Range[0, 1200]], PrimeQ] (* Michael De Vlieger, Apr 11 2016 *)

Prog

(PARI) lista(nn) = for (n=1, nn, if (isprime(p=sum(k=1, n, sumdigits(k))), print1(p, ", "))); \\ Michel Marcus, Apr 11 2016

Crossrefs

Cf. A000040, A037123, A271626.

Sequence in context: A006270 A248042 A139888 * A079594 A089922 A259848

Adjacent sequences: A271625 A271626 A271627 * A271629 A271630 A271631

Keyword

nonn,easy,base

Author

Paolo P. Lava, Apr 11 2016

Status

approved