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A225300 Terms in A025475 with palindromic base 2 representation. 0
1, 9, 27, 20457529, 87463589042698969 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..5.

PROG

(C)

#include <stdio.h>

#define TOP (1ULL<<32)  // if TOP is bigger,

int main() {  // SORT the output with your favorite tool.

  unsigned long long i, j, k, p;

  char *c = (char*)malloc(TOP/2);

  memset(c, 0, TOP/2);

  printf("1, ");

  for (i = 3; i < TOP; i+=2)

    if (c[i>>1]==0) {

      for (j=i*i; j<TOP; j+=i*2) c[j>>1]=1;

      for (j=i*i; ; j*=i) {

        for (p=0, k = j; k; k>>=1)  p+= p + (k&1);

        if (p==j)  printf("%llu, ", j);

        double d = ((double)j)*i;

        if (d >= ((double)TOP)*TOP) break;

      }

    }

}

CROSSREFS

Intersection of A006995 and A025475.

Cf. A029983.

Sequence in context: A124396 A020281 A075539 * A053825 A033479 A254139

Adjacent sequences:  A225297 A225298 A225299 * A225301 A225302 A225303

KEYWORD

nonn,base,more

AUTHOR

Alex Ratushnyak, May 04 2013

EXTENSIONS

Definition clarified by Chai Wah Wu, Mar 18 2018

STATUS

approved

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Last modified June 25 06:10 EDT 2019. Contains 324347 sequences. (Running on oeis4.)