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A176294 Numbers k such that sum of digits of k = sum of digits of k-th positive nonprime. 1
1, 15, 16, 17, 18, 19, 44, 45, 46, 47, 48, 116, 117, 118, 119, 245, 246, 290, 291, 292, 293, 294, 374, 375, 376, 425, 426, 427, 428, 429, 431, 432, 433, 434, 435, 436, 437, 438, 439, 441, 486, 487, 488, 489, 527, 528, 529, 580, 581, 582, 627, 628, 629, 684 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Jinyuan Wang, Table of n, a(n) for n = 1..10000

EXAMPLE

15 is a term because the 15th positive nonprime in A018252 is 24, and 1 + 5 = 2 + 4 = 6. - Bernard Schott, Feb 04 2019

MAPLE

A007953 := proc(n) add(d, d=convert(n, base, 10)) ; end proc:

A018252 := proc(n) option remember ; if n = 1 then 1; else for a from procname(n-1)+1 do if not isprime(a) then return a; end if; end do: end if; end proc:

for n from 1 to 900 do if A007953(n) = A007953(A018252(n)) then printf("%d, ", n) ; end if; end do: # R. J. Mathar, Apr 20 2010

PROG

(PARI) k=0; for(n=1, 684, k++; while(isprime(k), k++); if(sumdigits(n)==sumdigits(k), print1(n, ", "))) \\ Jinyuan Wang, Feb 04 2019

CROSSREFS

Cf. A018252.

Sequence in context: A004504 A296751 A297281 * A214424 A090461 A138598

Adjacent sequences:  A176291 A176292 A176293 * A176295 A176296 A176297

KEYWORD

nonn,base,less

AUTHOR

Juri-Stepan Gerasimov, Apr 14 2010

EXTENSIONS

More terms from R. J. Mathar, Apr 20 2010

STATUS

approved

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Last modified October 18 03:25 EDT 2021. Contains 348065 sequences. (Running on oeis4.)