A137443 First n-digit prime in consecutive digits of e.
7, 71, 281, 4523, 74713, 904523, 6028747, 72407663, 360287471, 7427466391, 75724709369, 749669676277, 8284590452353, 99959574966967, 724709369995957, 2470936999595749, 28459045235360287, 571382178525166427
Offset: 1
Examples
7427466391 is the first 10-digit prime found in consecutive digits of e, so a(10) = 7427466391.
Links
- Dan Drake, Table of n, a(n) for n = 1..1000
- Pegg, E. Jr. and Weisstein, E. W. Mathematica's Google Aptitude. MathWorld Headline news, Oct 13, 2004.
Crossrefs
Cf. A095926.
Programs
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Sage
def a(digits): bits = 0 pos = 0 while True: bits += (digits * 4) + 50 decimals = RealField(bits, rnd='RNDZ')(exp(1)).frac().str()[2:] for s in range(pos, len(decimals) - digits + 1): if decimals[s] != '0': i = Integer(decimals[s:s+digits]) if i.is_prime(): return i pos = len(decimals) - digits + 1
Comments