The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A242589 Primes p such that p = the cumulative sum of the digit-sum in base 15 of the digit-product in base 4 of each prime < p. 0

%I

%S 5,19,37,43,97,107,6091,6389,7121,21727,147107,148151,148279,148429,

%T 148469,172877,173209,173741,2621387,5642293,5642321,8932771,8981827,

%U 8981879,9094979,9095089,9997783,10010687,10010789,10037749,10144523,40179929,40365217,40379077,40379197,40386811,40612933

%N Primes p such that p = the cumulative sum of the digit-sum in base 15 of the digit-product in base 4 of each prime < p.

%F sum = sum + digit-sum(digit-mult(prime,base=4),base=15). The function digit-mult(n) multiplies all digits d of n, where d > 0. For example, digit-mult(1230) = 1 * 2 * 3 = 6. Therefore, the digit-sum in base 15 of the digit-mult(333) in base 4 = digit-sum(3 * 3 * 3) = digit-sum(1C) = 1 + C = 13. (1C in base 15 = 27 in base 10).

%e 5 = digit-sum(digit-mult(2,b=4),b=15) + sum(mult(3,b=4),b=15) = 2 + 3.

%e 19 = digit-sum(digit-mult(2,b=4),b=15) + sum(mult(3,b=4),b=15) + sum(mult(11,b=4),b=15) + sum(mult(13,b=4),b=15) + sum(mult(23,b=4),b=15) + sum(mult(31,b=4),b=15) + sum(mult(101,b=4),b=15) = 2 + 3 + 1 + 3 + 6 + 3 + 1.

%Y Cf. A240886 (similar sequence with digit sums in base 3).

%K nonn,base

%O 1,1

%A _Anthony Sand_, May 20 2014

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 1 05:02 EST 2022. Contains 358454 sequences. (Running on oeis4.)