A106721 - OEIS

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A106721

Largest of seven consecutive primes whose sum of digits is prime.

3301, 3307, 4201, 4441, 4447, 14347, 14369, 14387, 27127, 27143, 34259, 67217, 102121, 103069, 106181, 106187, 110647, 200159, 200171, 200177, 210097, 210101, 210109, 231827, 243109, 250147, 302941, 314641, 388903, 402223, 431807, 550061

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OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..2000

EXAMPLE

a(1)=3301 is a term because this is Largest of seven consecutive primes i.e. 3251,3253,3257,3259,3271,3299 and 3301, whose sum of digits is prime i.e. 3+2+5+1=11, 3+2+5+3=13, 3+2+5+7=17, 3+2+5+9=19, 3+2+7+1=13, 3+2+9+9=23 and 3+3+0+1=7.

MATHEMATICA

sdpQ[pr_]:=AllTrue[Total[IntegerDigits[#]]&/@pr, PrimeQ]; Transpose[Select[ Partition[ Prime[ Range[50000]], 7, 1], sdpQ]][[7]] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 09 2015 *)

CROSSREFS

Sequence in context: A242862 A078951 A236660 * A078969 A320717 A106724

Adjacent sequences: A106718 A106719 A106720 * A106722 A106723 A106724

KEYWORD

base,nonn

AUTHOR

Shyam Sunder Gupta, May 14 2005

STATUS

approved