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%I #24 Feb 19 2024 10:30:47
%S 2,3,5,7,17,19,29,59,79,89,199,389,499,599,997,1889,1999,2999,4999,
%T 6899,8999,29989,39989,49999,59999,79999,98999,199999,389999,598999,
%U 599999,799999,989999,2998999,2999999,4999999,6999899,8989999,9899999
%N Primes at which sum of digits strictly increases.
%H Eric M. Schmidt, <a href="/A061248/b061248.txt">Table of n, a(n) for n = 1..1000</a>
%e a(6) = 19, sum of digits is 10; a(7) = 29, sum of digits is 11 and 11 > 10.
%t t = {s = 2}; Do[If[(y = Total[IntegerDigits[x = Prime[n]]]) > s, AppendTo[t, x]; s = y], {n, 2, 750000}]; t (* _Jayanta Basu_, Aug 09 2013 *)
%o (Sage)
%o def A061248(nterms, b=10) :
%o res = []; n_list = [2]; n = 2; dsum = 0
%o while len(res) < nterms :
%o while not (sum(n_list) >= dsum and n.is_prime()) :
%o i = next((j for j in range(len(n_list)) if n_list[j] < b-1), len(n_list))
%o if i == len(n_list) : n_list.append(0)
%o n_list[i] += 1
%o r = dsum - sum(n_list[i:])
%o for j in range(i) :
%o n_list[j] = min(r, b-1)
%o r -= n_list[j]
%o n = sum(n_list[i]*b^i for i in range(len(n_list)))
%o res.append(n); dsum = sum(n_list)+1
%o return res
%o # _Eric M. Schmidt_, Oct 08 2013
%Y For the actual digit sums see A062132.
%K nonn,base
%O 1,1
%A _Amarnath Murthy_, Apr 23 2001
%E More terms from _Patrick De Geest_, Jun 05 2001
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