A106812 Smallest prime of the set of seven consecutive primes whose sum of digits is a set of seven distinct primes.

3511973, 5919931, 5919937, 20309959, 20309999, 21029951, 24129977, 66109973, 110003981, 152099951, 208334953, 235639951, 290111959, 316229981, 361344943, 387233993, 397629959, 418589981, 419804933, 444941957, 519014957, 522908993

Offset

1,1

Links

Table of n, a(n) for n=1..22.

Example

a(1)=3511973 is a term because sum of digits of seven consecutive primes i.e. (3511973, 3511993, 3511999, 3512011, 3512051, 3512053, 3512057), whose sum of digits (i.e. 29, 31, 37, 13, 17, 19, 23)is a set of seven distinct primes.

Prog

(PARI) dsum(n)=my(s); while(n, s+=n%10; n\=10); s
v=vectorsmall(10^6); i=0; forprime(p=2, prime(#v), v[i++]=dsum(p); if(!isprime(v[i]), v[i]=0))
for(i=1, #v-6, if(v[i]&&v[i+1]&&v[i+2]&&v[i+3]&&v[i+4]&&v[i+5]&&v[i+6]&&#vecsort(vector(7, j, v[i+j-1]), , 8)==7, print1(prime(i)", ")))
\\ Charles R Greathouse IV, Oct 26 2011

Crossrefs

Sequence in context: A205766 A183790 A256770 * A106811 A258687 A187314

Adjacent sequences: A106809 A106810 A106811 * A106813 A106814 A106815

Keyword

base,nonn

Author

Shyam Sunder Gupta, May 18 2005

Status

approved