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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A106782 Primes with digit sum = 53. 4
 989999, 1799999, 1889999, 1988999, 1989899, 1989989, 1997999, 1999799, 1999889, 1999979, 2699999, 2799899, 2799989, 2879999, 2899997, 2978999, 2979989, 2988899, 2989799, 2989997, 2998997, 2999879, 2999897, 3698999, 3789899 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS There are (1, 10, 23, 43, 87, 146, 255, 408, 642) terms below (1, 2, 3, ..., 9)*10^6. Among the 960 terms below 10^7, only {8998991, 8999981, 9899891, 9988991, 9997991, 9999971} end in the digit 1, only 30 end in the digit 3, and 268 end with a digit 7. - M. F. Hasler, Mar 09 2022 LINKS Michael S. Branicky, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Vincenzo Librandi) MATHEMATICA Select[Prime[Range[270000]], Total[IntegerDigits[#]]==53&] (* Harvey P. Dale, Apr 17 2011 *) PROG (Magma) [p: p in PrimesUpTo(3800000) | &+Intseq(p) eq 53]; // Vincenzo Librandi, Jul 09 2014 (PARI) select( {is_A106782(p)=sumdigits(p)==53&&isprime(p)}, primes([9e5, 4e6]\1)) \\ M. F. Hasler, Mar 09 2022 (Python) from itertools import count, islice from sympy import isprime from sympy.utilities.iterables import multiset_permutations def agen(b=10, sod=53): # generator for any base, sum-of-digits if 0 <= sod < b: yield sod nzdigs = [i for i in range(1, b) if i <= sod] nzmultiset = [] for d in range(1, b): nzmultiset += [d]*(sod//d) for d in count(2): fullmultiset = [0]*(d-1-(sod-1)//(b-1)) + nzmultiset for firstdig in nzdigs: target_sum, restmultiset = sod - int(firstdig), fullmultiset[:] restmultiset.remove(firstdig) for p in multiset_permutations(restmultiset, d-1): if sum(p) == target_sum: t = int("".join(map(str, [firstdig]+p)), b) if isprime(t): yield t if p[0] == target_sum: break print(list(islice(agen(), 25))) # Michael S. Branicky, Mar 10 2022 CROSSREFS Cf. similar sequences listed in A244918. Sequence in context: A328288 A328287 A083395 * A154674 A236034 A055617 Adjacent sequences: A106779 A106780 A106781 * A106783 A106784 A106785 KEYWORD nonn,base AUTHOR Zak Seidov, May 16 2005 STATUS approved

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 August 11 20:46 EDT 2024. Contains 375073 sequences. (Running on oeis4.)